ua 


or 

JAN  Dlt»0  I 


£6 


fi^ty 


/a/0  -  £  J  -^Tfa^f. 


AN    OUTLINE    OF    LOGIC 


BY 


BOYD  HENRY  BODE 

PROFESSOR  OF   PHILOSOPHY    IN   THE   UNIVERSITY  OF   ILLINOIS 


NEW  YORK 
HENRY  HOLT  AND  COMPANY 


Copyright,  1910, 

BY 

HENRY  HOLT  AND  COMPANY 


TO 
MY  MOTHER 


PREFACE 

The  aim  of  this  volume  is,  among  other  things,  to 
give  a  concrete  discussion  of  ambiguity,  to  simplify 
the  study  of  causal  connections,  and  to  treat  with 
greater  detail  than  is  usually  done  the  type  of  in- 
ference called  circumstantial  evidence,  the  nature  of 
proof,  and  the  postulates  of  reasoning.  The  place 
assigned  to  the  syllogism  is  relatively  small,  the  sub- 
ject being  presented  with  a  minimum  of  detail.  In 
the  distribution  of  emphasis,  the  function  of  logic 
as  a  guide  in  reasoning  has  been  constantly  borne  in 
mind.  It  is  partly  for  this  reason  that  the  illustra- 
tions are,  as  a  rule,  taken  from  other  sources  than  the 
physical  sciences,  because  I  incline  to  think  that  in 
the  past  these  latter  have  been  relied  upon  more 
than  is  desirable.  Finally,  I  have  added  a  chapter 
on  sense-perception,  in  the  hope  that  it  will  aid  in 
making  logic  a  propaedeutic  to  philosophy. 

A  word  or  two  of  explanation  may  be  in  place  re- 
garding the  discussion  of  causal  connections.  I  have 
ventured  to  depart  from  the  treatment  made  classic 
by  J.  S.  Mill,  because  the  treatment  in  question  seems 
to  me  to  be  neither  logically  nor  pedagogically  justi- 
fiable. In  the  first  place,  we  must  distinguish  between 
connections  that  are  universal  and  connections  that 
are  causal,  and  also  between  the  corresponding 
methods  of  proof.  While  a  universal  connection 
may  be  of  a  causal  character,  this  is  not  neces- 
sarily the  case.  Moreover,  the  causes  with  which 
we  habitually  deal  in  science  and  in  everyday  life 

v 


vi  PREFACE 

are  by  no  means  universally  followed  by  the  effects 
with  which  they  are  properly  correlated.  The  proof 
of  causal  connection  as  such  is  dependent,  I  think, 
upon  the  Method  of  Difference  alone.  It  is  not  neces- 
sary to  show  in  detail  that  Mill's  other  methods  intro- 
duce no  new  principle.  The  Method  of  Concomitant 
Variations,  for  example,  is  merely  the  Method  of 
Difference  as  applied  when  the  point  of  difference 
shows  quantitative  variations.  The  Joint  Method, 
which  Mill  himself  calls  the  Indirect  Method  of  Dif- 
ference, is  the  Method  of  Difference  as  applied  in 
comparisons  between  units  which  consist  of  groups 
instead  of  individual  cases.  The  Method  of  Agree- 
ment can  show,  at  most,  a  universal  connection,  with- 
out determining  the  character  of  the  connection. 
Ordinarily  the  cases  which  are  assigned  to  this 
method  fall  more  properly  under  the  '  Indirect  Method 
of  Difference,'  as  when  we  examine  the  connection 
between  water  supply  and  typhoid  fever.  And  the 
Method  of  Residues,  while  informing  us  that  the 
causes  already  known  are  not  sufficient  to  account  for 
the  total  effect,  neither  furnishes  a  clue  to  the  remain- 
ing cause  or  causes,  nor  enables  us  to  test  their  claim 
when  they  have  been  discovered. 

The  nature  of  my  obligations  to  other  writers,  par- 
ticularly to  Professor  James,  will  be  easily  discerned 
by  the  trained  reader  from  the  citations  and  refer- 
ences. I  wish,  further,  to  express  my  indebtedness  to 
my  former  colleagues  in  the  University  of  Wisconsin, 
Professors  E.  B.  McGilvary  and  F.  C.  Sharp,  who 
have  read  the  book  in  manuscript  and  aided  me 
with  numerous  valuable  criticisms  and  suggestions. 

B.  H.  B. 


CONTENTS 

CHAPTER  I 
INTRODUCTORY 

PAGE 

Reasoning  or  inference — The  definition  of  logic — The 
awareness  of  likeness  and  difference — Concepts  and  judg- 
ments— Concepts  and  classes — The  extension  and  inten- 
sion of  terms — The  imperfection  of  classification       .       .         1 

CHAPTER  II 

CLASSIFICATION  AND  CLASS  NAMES 

Undefined  similarity  and  metaphor — How  words  change 

in  meaning — Vagueness 11 

CHAPTER  III 

AMBIGUITY  AND  DEFINITION 

Illustrations  of  ambiguity — The  definition  of  ambiguity — ■ 
The  nature  and  purpose  of  definition — Definition  and 
synonym — Application  to  Law 24 

CHAPTER  IV 

SOME  SPECIAL  FORMS  OF  AMBIGUITY 

Why  ambiguities  are  classified — The  fallacy  of  accident — ■ 
Absolute  and  relative  terms — Concrete  and  abstract  terms      38 


viii  CONTENTS 

CHAPTER  V 

THE  NATURE  AND  INTERPRETATION  OF 
PROPOSITIONS 

PAGE 

Judgment  and  proposition — Categorical  and  conditional 
propositions — The  quality  and  quantity  of  propositions — 
The  distribution  of  terms — The  obversion  and  conversion 
of  propositions — False  obversion — False  conversion  .        .       51 

CHAPTER  VI 

THE  CATEGORICAL  SYLLOGISM 

The  purpose  of  the  syllogism — The  definition  of  the  syl- 
logism— The  parts  of  the  syllogism — The  inclusion  and 
exclusion  of  classes — The  rules  of  the  syllogism — The 
figures  of  the  syllogism — Reduction — Sorites,  or  chains 
of  reasoning — Inferences  in   quantitative  relations    .       .       65 

CHAPTER  VII 

HYPOTHETICAL   AND   DISJUNCTIVE   SYLLOGISMS 

The  hypothetical  syllogism— The  disjunctive  syllogism— 
The  dilemma — The  relation  of  categorical  and  conditional 
syllogisms — The  function  of  the  syllogism   ....       81 

CHAPTER  VIII 

FALSE  ASSUMPTION  OR  BEGGING  THE  QUESTION 

Incomplete  arguments— The  definition  of  false  assumption 
— False  assumption,  ambiguity,  and  imperfect  disjunc- 
tion—False assumption  and  the  syllogism— Two  special 
forms  of  false  assumption:  (a)  Reasoning  in  a  circle, 
(b)   Irrelevancy,  or  ignoring  the  question  ....       93 


CONTENTS  ix 

CHAPTER  IX 
THE  PROOF  OF  UNIVERSAL  CONNECTIONS 

PAGE 

Proof  by  enumeration — Proof  by  the  Method  of  Agree- 
ment— The  principle  of  uniformity — Uniformity  as  a 
postulate — The  impossibility  of  varying  all  irrelevant  cir- 
cumstances— Reasonable  doubt — Conversion — Mathemati- 
cal propositions 107 

CHAPTER  X 

THE  PROOF  OF  CAUSAL  CONNECTIONS 

Causation — Group  comparisons — The  Method  of  Differ- 
ence— Plurality  of  points  of  difference — Plurality  of 
causes — Merely  apparent  points  of  difference — Inference 
to  other  cases — Proof  of  causation  as  dependent  upon 
number  of  instances — Concomitant  variations     .        .        .     123 

CHAPTER  XI 

PROBABILITY 

Judgments  of  probability  as  based  upon  classes — The  con- 
stancy of  classes — The  nature  of  probability — How  prob- 
ability is  made  more  accurate — The  principle  implied  in 
estimates  of  probability — The  function  of  numbers  in  esti- 
mates of  probability — Probability  as  based  upon  indi- 
vidual resemblances — The  nature  of  analogy — Analogy 
and  classification — False  analogy — The  value  of  analogy 
— The  relation  of  analogy  to  circumstantial  evidence        .     148 

CHAPTER  XII 

CIRCUMSTANTIAL  EVIDENCE  AND  THE  TEST  OF 
TRUTH 

The  nature  of  circumstantial  evidence — Examples — The 
test  of  truth — Competing  explanations — The  function  of 
reasonable  doubt — Probability  and  certainty — Hypothesis, 
theory,  and  fact — The  fallacies  of  circumstantial  evidence     170 


x  CONTENTS 

CHAPTER  XIII 
OBSERVATION  AND  MEMORY 

PAGE 

The  popular  notion  of  observation — Difficulties  of  the 
view — How  association  is  determined — Memory — The 
problem  involved — The  solution  of  the  problem — Observa- 
tion and  explanation •  198 

CHAPTER  XIV 

THE  NATURE  OF  REASONING 

The  definition  of  reasoning— Logical  necessity — Judgment 
and  inference — The  reasoning  of  animals — Why  some 
persons  reason  better  than  others — The  development  of 
inference — Deduction,  induction,  and  circumstantial 
evidence 21^ 

CHAPTER  XV 

THE  AUTHORITY  OF  THE  TEST  OF  TRUTH 

The  argument  for  scepticism — Criticism  of  the  argument — 
Unreasoned  scepticism— The  non-rational  basis  for  the 
test  of  truth— To  what  extent  our  interests  may  properly 
determine  belief— Belief  and  evidence— Mysticism  and  the 
test  of  truth 236 

CHAPTER  XVI 
THE  PROBLEM  OF  SENSE-PERCEPTION 


The  subjectivity  of  sense-qualities— Primary  and  second- 
ary qualities 


Exebcises 
Index      . 


255 

269 
321 


AN   OUTLINE   OF  LOGIC 


AN  OUTLINE  OF  LOGIC 

CHAPTER  I 

INTRODUCTORY 

Reasoning  or  Inference. —  The  special  subject-mat- 
ter of  logic  is  reasoning.  What  is  meant  by  reason- 
ing is  shown  most  simply  through  contrast  with  what 
is  not  reasoning.  Some  facts  may  be  known  imme- 
diately or  at  first  hand,  while  others  are  known 
through  certain  mental  processes  called  reasoning  or 
inference.  The  former  kind  of  knowledge  is  independ- 
ent of  any  experience  other  than  the  one  of  the 
present  moment,  while  the  latter  is  not.  Thus  we 
need  no  information  outside  the  fact  itself  to  inform 
us  that  the  ache  of  a  decaying  tooth  is  disagreeable, 
or  that  the  flame  of  a  lighted  candle  is  bright.  These 
facts  are  known  directly,  with  no  help  from  other 
facts.  They  can  be  experienced  by  the  child  as  well 
as  by  the  adult.  But  if  we  say  that  the  ache  will  stop 
when  the  tooth  is  pulled,  or  that  the  flame  will  burn 
the  hand  with  which  it  comes  in  contact,  the  situation 
is  different.  In  order  to  know  this,  we  must  have 
information  based  upon  other  experiences  than  the 
experience  of  the  ache  or  the  burn.  The  knowledge 
that  the  fire  before  us  will  burn  is  not  immediate  but 
mediate,  i.e.,  it  is  acquired  through  our  knowledge 


2  AN  OUTLINE  OF  LOGIC 

of  other  facts.  As  a  provisional  statement,  therefore, 
we  may  say  that  reasoning  or  inference  occurs  when- 
ever we  assert  something  to  be  true  on  the  ground 
that  something  else  is  true.  When  the  reasoning  is 
intended  to  convince  some  one  else  of  the  truth  of  the 
assertion,  it  is  usually  called  argument. 

Good  and  Bad  Reasoning. — We  all  know  from  ex- 
perience that  there  is  good  reasoning  and  bad  reason- 
ing. If  we  say  that  B  is  true  because  A  is  true, 
A  and  B  are  supposed  to  be  so  related  that  the  belief 
in  A  involves  the  belief  in  B.  But  we  may  be  mis- 
taken in  this  relation,  in  which  case  our  conclusion 
that  B  is  true  does  not  '  follow.'  According  to 
some  accounts,  the  wise  men  of  Spain  argued  with 
Columbus  that  he  could  not  reach  India  by  sailing 
west,  because  if  the  earth  were  round,  as  he  asserted, 
he  would  at  some  time  reach  a  point  where  the  ship 
would  be  going  down  hill  and  ultimately  fall  off, 
just  as  a  miniature  vessel  would  fall,  if  it  should 
attempt  to  travel  around  an  artificial  globe.  If  A  is 
true  (earth  round),  B  must  be  true  (circumnavigation 
impossible).  If  there  is  a  resemblance  between  earth 
and  artificial  globe  in  contour  of  surface,  there  must 
be  a  further  resemblance,  so  it  was  held,  in  the  rela- 
tion of  each  to  the  objects  upon  its  surface.  In  the 
same  way  we  reason  that  because  the  fire  which  we 
see  resembles  other  fires  in  its  general  appearance,  it 
resembles  these  other  fires  also  in  burning  the  hand 
that  comes  too  near.  Both  arguments  are  based  upon 
resemblance,  but  the  one  is  correct  while  the  other 
is  not.  In  making  their  comparison,  the  wise  men 
overlooked  an  important  point  of  difference,  viz.,  that 
for  an  object  on  the  artificial  globe  the  point  towards 


INTRODUCTORY  3 

which  it  gravitates  is  outside  the  globe,  while  for 
objects  on  the  earth  this  point  is  within  the  earth 
itself. 

A  somewhat  different  form  of  bad  reasoning  is  the 
inference  that  certain  things,  such  as  seeing  the  moon 
over  the  right  shoulder,  will  bring  good  luck,  or  that 
certain  '  charms  '  will  ward  off  evil.  Such  beliefs 
are  usually  based  on  a  coincidence  that  is  interpreted 
to  mean  a  causal  relation.  Here  the  inference  is 
guided,  not  by  resemblance,  but  by  difference — by  the 
difference  in  the  state  of  affairs  before  and  after  the 
alleged  cause  made  its  appearance.  The  advertise- 
ments of  patent  medicines,  with  pictures  to  show  the 
difference  between  before  and  after  taking,  furnish 
another  illustration  of  the  point.  The  belief  in  B — 
that  the  second  event  is  the  effect  of  the  first — is 
based  upon  the  belief  in  A — that  the  alleged  cause 
was  the  only  circumstance  which  was  present  to  dis- 
turb the  existing  conditions. 

It  will  appear  more  fully  as  we  proceed,  that  all 
reasoning,  both  good  and  bad,  goes  back,  in  the  end, 
to  the  awareness  of  resemblance  or  difference.  As 
suggested  by  the  illustrations  just  given,  the  correct- 
ness of  reasoning  depends  upon  the  success  with  which 
the  selection  of  resemblances  or  differences  is  made. 
The  important  question,  therefore,  is,  How  can  we 
know  when  we  have  selected  the  points  of  resemblance 
or  difference  that  are  necessary  to  prove  our  point? 

The  Definition  of  Logic. — The  reasoning  by  which 
a  fact  is  supported,  or  upon  which  the  assertion 
of  a  fact  is  based,  is  commonly  called  the  evidence 
or  proof  for  the  fact.  Unless  otherwise  specified,  we 
shall   use   the    words    '  fact  '    and    '  thing  '    in    the 


/ 


4  AN  OUTLINE  OF  LOGIC 

widest  sense,  as  inclusive  of  anything  positive  or 
negative  about  which  a  statement  can  be  made.  "When 
the  reasoning  seems  to  be  trustworthy  but  is  not  so 
in  reality,  it  is  called  a  fallacy.  The  existence  of 
fallacy  makes  it  necessary  to  reflect  upon  reasoning, 
in  order  to  determine  how  fallacies  arise  and  wherein 
proof  consists.  Logic  is  sufficiently  defined  for  our 
purposes  if  we  say  that  it  is  the  science  of  proof  or 
evidence* 

If  we  are  to  learn  the  difference  between  good 
reasoning  and  bad  reasoning,  we  must  know  something 
about  reasoning  in  general.  By  ascertaining  how  rea- 
soning proceeds,  wiiat  methods  it  employs,  and  what 
assumptions  it  makes,  we  may  discover  what  final 
test  or  standard  it  implies,  and  how  fallacies  occur. 
This  final  test  will  be  stated  when  we  have  made  a 
survey  of  the  field.  Our  first  concern  will  be  to 
discuss  actual  reasoning  in  some  of  its  phases,  and 
the  fallacies  incident  to  reasoning. 

The  Awareness  of  Likeness  and  Difference. — 
The  awareness  of  likeness  and  difference  means  that 
we  put  together  things  which  in  some  respects  are 
different  from  each  other,  and  that  we  discriminate  be- 
tween things  which  in  some  respects  are  alike.  It  means, 
therefore,  that  to  some  extent  we  resolve  things  men- 
tally into  their  elements,  because  we  pick  out  their 
points  of  likeness  and  of  difference  and  set  them 
over  against  each  other.  In  the  act  of  noticing  a 
resemblance  we  also  take  some  account  of  the  differ- 
ence, for  if  we  did  not,  we  should  not  distinguish  the 
two  resembling  things  at  all,  and  hence  not  be  aware 
of  any  resemblance.    All  resemblance  involves  differ- 

*  Cf.  J.  S.  Mill,  System  of  Logic,  Introduction. 


INTRODUCTORY  5 

ence,  and  all  difference  involves  resemblance;  but  in 
reasoning  it  is  sometimes  the  resemblance  and  some- 
times the  difference  which  is  important  and  which  be- 
comes the  object  of  our  chief  attention. 

Concepts  and  Judgments. — We  resolve  things 
mentally  into  their  elements  by  noticing  their  re- 
semblances and  differences  when  compared  with  other 
things.  This  process  of  dissection  is  a  process  that 
involves  both  analysis  and  abstraction.  An  object 
like  a  box,  for  example,  we  break  up  in  thought  into 
its  various  parts,  and  this  phase  of  the  process  is 
called  analysis.  Then  we  retain  one  of  these  elements, 
say  squareness,  and  discard  the  rest.  This  is  called 
abstraction  (Latin  al),  and  trahere,  to  draw  away 
from),  because  the  element  has  now  been  isolated 
from  its  setting.  This  quality  we  can  thereafter 
recognize  in  the  most  diverse  contexts,  such  as  square 
buildings,  square  tables,  and  square  areas  of  land; 
we  know  that  whatever  things  resemble  each  other 
in  being  square,  resemble  each  other  also  in  the  pos- 
session of  the  geometrical  qualities  that  go  with 
squareness.  This  attribute  of  squareness  in  its  de- 
tached form  is  called  a  concept  or  idea.  We  can 
have  ideas  of  attributes,  such  as  '  squareness,'  or  of 
individual  things,  such  as  '  this  flash  of  lightning,' 
or  of  '  London,'  etc.;  or  of  classes,  such  as  '  men,' 
1  fish, '  etc. ;  all  of  them  being  formed  by  the  process 
of  analysis  and  abstraction.  Owing  to  this  abstrac- 
tion, ideas  possess  a  fixity  which  is  not  found  in  sense- 
perception.  Perceptions  are  changeable  and  transi- 
tory; whereas  we  can  refer  at  different  times  to  an 
idea  as  the  same  idea  that  we  had  before.  ' '  The  func- 
tion by  which  we  mark  off,  discriminate,  draw  a  line 


6  AN  OUTLINE  OF  LOGIC 

round,  and  identify  a  numerically  distinct  subject  of 
discourse  is  called  conception, ' '  *  and  the  mental 
product  of  this  act  of  conception  is  called  a  concept, 
idea,  or  meaning.  A  judgment  on  the  other  hand  is 
sufficiently  defined  for  the  present  if  we  say  that 
it  is  the  affirmation  or  denial  of  an  idea,  i.e.,  the  asser- 
tion of  something  as  true  or  false. 

Concepts  and  Classes. — Leaving  aside  individual 
ideas  for  the  present,  we  find  that  all  ideas  imply 
classification,  for  they  are  all  ideas  of  something  that 
can  find  embodiment  in  more  than  one  instance.  They 
are  formed  by  the  isolation  of  some  attribute  or  set 
of  attributes  that  are  common  to  a  number  of  different 
cases.  It  is  true  that  we  often  do  not  think  of  the 
different  instances  in  which  the  attribute  in  question 
is  embodied.  When  we  say,  "  Honesty  is  the  best 
policy,"  or  "  Virtue  is  its  own  reward,"  we  do  not 
necessarily  make  any  conscious  reference  to  the  differ- 
ent instances  of  honesty  or  virtue  of  which  these  say- 
ings hold  true.  But  unless  the  existence,  in  some  sense 
or  other,  of  these  different  instances  is  taken  for 
granted,  the  assertions  have  no  meaning.  Words, 
therefore,  which  designate  attributes  may  be  taken 
as  class  names  whenever  it  suits  our  purpose  to  do  so. 
"  By  a  class  will  here  be  meant  any  imagined  group 
of  individual  cases,  whether  material  things  or  im- 
material, whether  real  or  unreal, — a  group  in  which 
every  individual  is  supposed  to  resemble  all  the  others 
in  some  respects,  though  differing  in  others.  There 
are  classes  of  actions  and  events  just  as  of  anything 
else;  'miracle'  is  a  class  name,  for  instance;  or 
1  coronation/  '  battle,'  '  eclipse  ';  in  fact  any  name 
•James,  Psychology   (Briefer  Course),  p.  239. 


INTRODUCTORY  7 

which  is  used  so  as  to  admit  of  a  plural, — either 
simply,  as  '  miracles,'  '  negroes,'  '  battles,'  or  in  the 
more  circuitous  form  of  '  pieces  of  gold,'  '  cases  of 
deceit, '  and  so  on. "  * 

As  this  quotation  indicates,  a  class  name  may  con- 
sist of  more  than  one  word.  Any  word  or  group  of 
words  which  serves  to  point  out  any  imaginable  sub- 
ject of  discourse  is  looked  upon  as  a  name  or  term. 
If  the  name  is  one  that  is  applicable  in  the  same  sense 
to  a  number  of  different  cases,  the  name  may  be  re- 
garded as  a  class  name.  Nor  does  it  matter  how 
temporary  or  artificial  the  group  may  be.  "  The  men 
who  at  the  risk  of  their  lives  entered  the  burning 
building  in  order  to  rescue  the  occupants  "  is  as  much 
a  class  name  as  '  dog,'  or  '  tree,'  or  '  justice.' 
Moreover,  the  existence  of  classes  is  implied  in  ad- 
jectives and  verbs  as  well  as  in  nouns.  To  say,  for 
example,  that  appearances  are  deceptive,  means  that 
appearances  belong  to  the  class  of  things  which  are 
deceptive.  And  in  '  flowers  grow  '  the  word 
1  grow  '  points  to  a  class  of  objects  which  have  the 
common  characteristic  of  growth.  Adjectives  and 
verbs,  therefore,  are  class  names  in  so  far  as  they  are 
names  which  are  not  confined  to  a  single  thing  but 
applicable  in  the  same  sense  to  a  group  of  things. 

The  Extension  and  Intension  of  Terms. — It  has 
been  shown  that  class  names  have  two  aspects;  they 
apply  to  a  certain  group  of  objects  or  '  things,' 
and  they  indicate  certain  attributes  or  characters. 
The  size  of  the  group  to  which  the  term  applies  deter- 
mines the  extension  of  the  name,  while  the  qualities 
for  which  it  stands  represent  or  determine  the  inten- 
*  Sidgwick,  The  Use  of  Words  in  Reasoning,  p.  150. 


8  AN  OUTLINE  OF  LOGIC 

sion  of  the  name.  Instead  of  extension  and  intension, 
the  terms  denotation  and  connotation  are  sometimes 
used.  As  one  writer  says,  "  The  denotation  of 
a  name  consists  of  the  things  to  which  it  applies, 
the  connotation  consists  of  the  properties  which  it 
implies. "  * 

The  Importance  of  Classification. — We  have  seen 
that  classes  are  formed  in  every  case  on  the  basis 
of  certain  attributes  or  characters  that  are  common 
to  the  class.  As  this  world  of  ours  is  constituted, 
such  an  attribute  or  character  may  imply  another, 
so  that  it  serves  as  a  sign  of  this  other.  If,  therefore, 
we  put  into  the  same  class  the  things  that  are  alike 
in  some  particular  quality,  we  may  be  enabled  to 
know  in  advance  what  to  expect  from  the  entire  class. 
To  take  a  simple  illustration,  if  we  abstract  the  at- 
tribute '  fire  '  from  one  of  its  special  forms,  whether 
as  a  lighted  candle,  a  burning  match,  or  a  bonfire,  one 
unpleasant  experience  with  fire  will  be  sufficient  to  put 
us  on  our  guard  against  all  the  rest.  By  such  a  proc- 
ess of  abstraction  and  classification,  the  child  learns 
that  sugar  is  sweet ;  that  water  will  quench  the  thirst ; 
that  crockery  will  break  if  dropped  to  the  floor,  while 
a  rubber  ball  will  not ;  that  glass  will  cut  the  fingers, 
while  sticks  may  be  handled  with  safety;  and  so  on 
throughout  the  whole  round  of  its  little  existence. 
In  adults  we  have,  of  course,  the  same  sort  of  thing, 
only  on  a  larger  and  more  complex  scale. 

Classification  is,  in  short,  a  device  whereby  we  are 

enabled   to   simplify   tremendously    an    environment 

which  would  otherwise  be  too  complex  for  any  finite 

intelligence.     If  we  were  obliged  to  become  directly 

*Bosanquet,  The  Essentials  of  Logic,   p.   88. 


INTRODUCTORY  9 

acquainted  with  every  object  and  every  event,  i.e.,  if 
things  were  entirely,  and  not  merely  partly,  different 
from  each  other,  adjustment  would  be  impossible,  since 
we  should  be  unable  to  forecast  the  behavior  of  any- 
thing. We  can  anticipate  the  future  and  construe  the 
past  because  certain  things  behave  alike  in  certain 
respects.  We  can  prove  that  certain  things  have  hap- 
pened in  the  past  because  we  know  what  kind  of  causes 
are  necessary  to  produce  the  given  effects;  we  can 
foretell  the  future  because  we  know  what  effects 
will  be  produced  by  the  given  causes;  we  are  able 
to  resort  to  proof  because  certain  things  can  be  de- 
pended upon  to  go  together. 

The  Imperfection  of  Classification. — It  has  been 
stated  that  the  awareness  of  likeness  and  differ- 
ence leads  to  the  formation  of  ideas  and  that  this 
in  turn  involves  classification.  If  the  attribute  in 
reference  to  which  the  classification  was  made  is  shown 
to  be  an  invariable  sign  of  some  other  attribute,  we 
are  in  possession  of  knowledge  that  holds  for  the 
entire  class.  But  in  order  to  acquire  such  knowledge 
the  classification  must  be  made  with  sufficient  care  to 
bring  out  the  point  of  resemblance  that  is  common 
to  the  class.  As  a  matter  of  fact,  however,  this  re- 
semblance is  not  always  clearly  discriminated.  We 
may  classify  without  knowing  clearly  wherein  the  dif- 
ferent eases  that  are  put  into  the  same  class  resemble 
each  other.  Whenever  this  happens  there  is  danger 
that  we  may  take  the  wrong  attribute  as  a  sign  of 
the  second  attribute.  Such  confusion  is  apparently 
at  the  basis  of  the  assertion, ' '  Nor  are  we  much  moved 
by  the  objection  that  it  is  wrong  to  enter  the  liquor 
trade,  which  appears  to  us  just  as  legitimate  as  any 


10  AN  OUTLINE  OF  LOGIC 

other. ' '  *  The  line  of  reasoning  by  which  the  writer 
apparently  reaches  his  conclusion  is  as  follows: 
(1)  Whatever  is  (morally)  right  is  blameless.  (2)  A 
man  has  a  good  (legal)  right  to  engage  in  the  liquor 
business;  and  therefore  (3)  The  liquor  business  is 
(morally)  blameless.  Persons  who  charge  exorbitant 
rates  of  interest  are  apt  to  reason  in  a  similar  way. 
Moral  right  and  legal  right  are  classed  together,  and 
no  distinction  is  made  between  the  two.  The  fact 
that  they  are  classed  together  indicates  that  they  are 
alike  in  certain  respects,  viz.,  in  the  conformity  to  a 
standard.  The  standard  differs,  however,  in  the  two 
cases.  We  cannot  say  that  whatever  is  in  conformity 
to  a  standard  is  blameless,  but  only  what  is  in  con- 
formity with  the  moral  standard.  This  distinction 
is  not  made,  because  in  classing  moral  right  and  legal 
right  together  we  do  indeed  recognize  a  resemblance, 
but  we  do  not  take  the  pains  to  discover  wherein 
they  are  alike  and  wherein  they  are  different,  with 
the  result  that  the  undefined  resemblance  is  taken  as 
a  reliable  sign  of  the  second  attribute,  '  blameless.' 
If  our  ideas  always  involved  sufficient  analysis,  such 
errors  would  not  occur.  But  if  these  fallacies  are  to 
be  properly  appreciated  we  must  know  how  classifica- 
tions are  actually  made  and  how  the  shortcomings  of 
our  classifications  are  intensified  by  the  names  that 
are  applied  to  them.  The  consideration  of  these  topics, 
therefore,  will  be  our  next  undertaking. 
*  Fortnightly  Review,  Vol.  27,  p.  2. 


CHAPTER  II 

CLASSIFICATION  AND  CLASS  NAMES 

It  has  been  pointed  out  that  by  means  of  classifica- 
tion we  are  enabled  to  simplify  an  environment  which 
would  otherwise  be  much  too  complex  for  rational 
conduct.  Things  that  are  found  to  be  alike  are  called 
by  the  same  name,  and  we  ordinarily  proceed  on  the 
assumption  that  the  point  of  resemblance  which  we 
have  discovered  and  on  the  strength  of  which  the 
name  has  been  applied,  is  invariably  related  to  some 
other  quality,  so  that  we  know  beforehand  the  nature 
of  the  entire  class.  Since  classification  is  so  important, 
it  is  not  a  matter  of  accident  that  we  apply  the  same 
name  to  things  which  resemble  each  other  in  certain 
respects.  Now  if  names  were  perfect  instruments, 
they  would  indicate  wherein  the  different  things  are 
alike.  They  would  be  names  for  the  common  points 
of  resemblance  and  nothing  more.  The  point  of  re- 
semblance being  known,  we  could  ascertain  what  qual- 
ity or  attribute  goes  with  it,  if  any.  But  this  ideal 
is  not  often  realized.  In  the  case  of  simple  attributes 
such  as  squareness,  straightness,  duration,  etc.,  the 
point  of  resemblance  is  sufficiently  well  understood 
for  most  purposes.  Then  there  are  certain  '  natural  ' 
groups,  which  for  all  ordinary  purposes  can  be  in- 
dicated by  a  class  name  with  little  danger  of  error, 
even  though  we  do  not  know  very  precisely  what  the 

11 


12  AN  OUTLINE  OF  LOGIC 

nature  of  the  resemblance  may  be.  It  is  usually  safe 
to  speak  of  '  men,'  '  horses,'  '  trees,'  and  similar 
objects  and  to  draw  certain  inferences  concerning 
them,  in  spite  of  the  fact  that  we  are  unable  to  define 
these  terms.  But  even  if  we  grant  that  terms  like 
the  above  are  not  likely  to  cause  trouble,  there  is  still 
a  large  group  of  terms  such  as  '  capital,'  '  labor,' 
1  religion,'  '  education,'  '  government,'  etc.,  which, 
owing  to  their  vagueness,  are  the  source  of 
endless  confusion.  When  the  nature  of  the  resembling 
qualities  is  not  known,  the  terms  are  almost  sure  to 
mean  different  things  on  different  occasions,  with  the 
result  that  what  is  true  of  some  members  of  the  class 
only,  is  taken  to  be  true  of  all. 

Undefined  Similarity  and  Metaphor. — A  study  of 
language  soon  reveals  the  fact  that  clearly  defined 
ideas  and  correspondingly  definite  class  names  are 
not  to  be  found  in  the  early  stages  of  thought  and 
language,  but  presuppose  development  and  effort.  In 
order  to  understand  the  development  of  ideas  and 
language,  it  is  necessary  to  realize  that  a  resemblance 
may  be  '  felt  '  before  we  know  wherein  it  consists. 
The  fact  that  the  nature  of  the  resemblance  which 
underlies  the  extension  of  a  name  need  not  at  the 
outset  be  clearly  apprehended,  is  both  curious  and 
significant.  It  is  possible  to  see  a  resemblance  among 
different  things,  and  yet  be  utterly  at  a  loss  to  know 
just  wherein  the  resemblance  consists.  Thus  a  per- 
son may  be  a  good  judge  of  faces  and  be  able  to 
classify  them  with  considerable  skill  as  good  or  bad, 
but  his  ability  to  give  reasons  for  his  opinions  may 
lag  woefully  behind.  He  does  not  know  just  why  he 
judges  as  he  does.    There  is  something  in  the  criminal 


CLASSIFICATION  AND  CLASS  NAMES        13 

type  of  face,  for  example,  which  he  somehow  detects 
at  once  and  which  fills  him  with  aversion,  and  yet 
he  is  unable  to  point  out  what  it  is.  The  common 
attribute  or  point  of  resemblance  is  '  felt  '  rather 
than  distinctly  conceived.  Physiognomy  is  a  study 
that  attempts  to  analyze  out  those  common  character- 
istics which  enable  us  to  classify  faces  as  we  do.  We 
classify  them,  not  through  blind  instinct,  but  on  the 
basis  of  an  unanalyzed  resemblance. 

Whenever  the  similarity  is  so  intangible  that  we 
are  unable  to  specify  the  point  of  resemblance,  we 
can  only  indicate  the  resemblance  by  describing  one 
thing  in  terms  of  another,  i.e.,  by  means  of  a  meta- 
phor. The  use  of  a  metaphor,  so  far  as  we  are  at 
present  concerned,  means  the  application  of  a  name 
that  stands  for  a  complex  of  attributes  to  some  object 
or  thing  which  possesses  only  a  portion  of  these  at- 
tributes, without  specifying  which  of  the  attributes 
are  possessed  by  the  object  or  thing  in  question.  To 
take  a  familiar  illustration,  the  statement  that  the 
camel  is  the  ship  of  the  desert  is  metaphorical,  for 
while  the  camel  is  a  ship  in  some  respects,  it  is  not 
a  ship  in  every  respect.  The  word  '  ship  '  includes 
a  complex  of  attributes,  and  the  statement  does  not 
make  clear  which  of  these  attributes  it  means  to  ascribe 
to  the  camel.  In  a  similar  way,  we  speak  of  a  person 
as  being  '  metallic  ';  or,  to  borrow  an  illustration 
from  Professor  James,  we  may  describe  a  family  as 
having  '  blotting-paper  '  voices.  Such  terms  are  uni- 
versally recognized  as  metaphors. 

1 '  The  mode  in  which  words  are  learnt  and  extended 
may  be  studied  most  simply  in  the  nursery.  A  child, 
say,  has  learnt  to  say  mambro  when  it  sees  its  nurse. 


14  AN  OUTLINE  OF  LOGIC 

The  nurse  works  a  hand-turned  sewing  machine,  and 
sings  to  it  as  she  works.  In  the  street  the  child 
sees  an  organ-grinder  singing:  it  calls  mambro:  the 
nurse  catches  the  meaning  and  the  child  is  overjoyed. 
The  organ-grinder  has  a  monkey:  the  child  has  an 
india-rubber  toy;  it  calls  this  also  mambro.  The  name 
is  extended  to  a  monkey  in  a  picture-book.  It  has  a 
toy  musical  box  with  a  handle ;  this  also  becomes 
mambro,  the  word  being  extended  along  another  line 
of  resemblance.  A  stroller  with  a  French  fiddle  comes 
within  the  denotation  of  the  word :  a  towel-rail  is 
also  called  mambro  from  some  fancied  resemblance  to 
the  fiddle.  A  very  swarthy  hunchback  mambro  fright- 
ens the  child:  this  leads  to  the  transference  of  the 
word  to  a  terrific  coalman  with  a  bag  of  coals  on  his 
back.  In  a  short  time  the  word  has  become  a  name 
for  a  great  variety  of  objects  that  have  nothing 
whatever  in  common  to  all  of  them,  though  each  is 
strikingly  like  in  some  point  to  a  predecessor  in  the 
series.  "When  the  application  becomes  too  heter- 
ogeneous, the  word  ceases  to  be  of  use  and  is  gradually 
abandoned,  the  most  impressive  being  the  last  to  go. 
In  a  child's  vocabulary  where  the  word  mambro  had 
a  run  of  nearly  two  years,  its  last  use  was  an  adjective 
signifying  ugly  or  horrible."  * 

The  history  of  the  child,  as  just  exemplified,  merely 
epitomizes  the  history  of  the  race.  ' '  The  first  words  are 
probably  names  of  entire  things  and  entire  actions,  of 
extensive  coherent  groups.  A  new  experience  in  the 
primitive  man  can  only  be  talked  about  by  him  in  terms 
of  the  old  experiences  which  have  received  names. 
It  reminds  him  of  certain  ones  from  among  them,  but 
*  Minto,  Logic,  p.  83. 


CLASSIFICATION  AND  CLASS  NAMES        15 

the  points  in  which  it  agrees  with  them  are  neither 
named  nor  dissociated.  Pure  similarity  must  work 
before  the  abstraction  can  work  which  is  based  upon 
it.  The  first  adjectives  will  therefore  probably  be 
total  nouns  embodying  the  striking  character.  The 
primeval  man  will  say,  not  '  the  bread  is  hard,'  but, 
'  the  bread  is  stone  ';  not  '  the  face  is  round,'  but, 
1  the  face  is  moon  ' ;  not '  the  fruit  is  sweet, '  but,  '  the 
fruit  is  sugar-cane. '  The  first  words  are  thus  neither 
particular  nor  general,  but  vaguely  concrete;  just  as 
we  speak  of  an  '  oval  '  face,  a  'velvet  '  skin,  or  an 
'  iron  '  will,  without  meaning  to  connote  any  other 
attributes  of  the  adjective-noun  than  those  in  which 
it  does  resemble  the  noun  it  is  used  to  qualify. ' '  * 

The  inevitable  tendency  of  the  process  just  described 
is  to  make  the  point  of  resemblance  stand  out  promi- 
nently amid  the  different  settings.  As  the  number 
and  variety  of  instances  increase,  we  not  only  learn 
to  recognize  the  resembling  quality  readily,  but  we 
also  succeed  in  distinguishing  it  from  its  different 
contexts.  The  resemblance  is  no  longer  merely  felt, 
but  is  clearly  conceived,  i.e.,  a  concept  is  formed. 

How  Words  Change  in  Meaning. — It  has  been 
indicated  how  the  use  of  names  involves  a  process  of 
differentiation.  By  grouping  different  things  together, 
both  the  resemblances  and  the  differences  tend  to 
become  prominent.  As  this  differentiation  goes  on, 
the  function  of  the  names  employed  is  bound  to 
undergo  a  change.  The  change  may  occur  in  a  vari- 
ety of  different  ways.  In  the  first  place,  the  name  may 
come  to  be  limited  to  the  attribute  which  is  found 
to  be  common  to  the  whole  class.  Thus  the  word 
*  James,  Psychology,  Vol.  II.,  p.  365. 


1G  AN  OUTLINE  OF  LOGIC 

'oval,'  in  the  quotation  just  cited,  no  longer  con- 
notes '  egg,'  but  points  out  one  specific  quality,  viz., 
a  certain  shape.  In  a  similar  way  the  word  '  fluid,' 
which  to  the  minds  of  many  persons  suggests  in- 
definitely nearly  all  the  qualities  of  water,  is  narrowed 
down  to  a  single  quality,  when  a  comparison  between 
water  and  gases  teaches  us  to  distinguish  between 
moisture  and  mobility  of  parts. 

Secondly,  the  word  in  question  may  be  confined  to 
one  of  the  special  meanings  that  have  been  made 
explicit  by  the  differentiation.  Thus  '  attention  ' 
meant  originally  a  '  stretching-to, '  and  its  applica- 
tion to  a  mental  attitude  rests  upon  the  resemblance 
between  this  attitude  and  the  physical  fact.  At 
present,  however,  the  word  is  restricted  to  the  mental 
attitude.  Similarly  the  word  '  prevent  '  meant 
originally  a  '  coming-before  ';  a  meaning  which  sur- 
vives in  the  Scriptural  passage,  "  I  prevented  the 
dawning  of  the  morning  "  (Ps.  119: 147).  From  this 
meaning  it  is  but  a  step  to  the  coming-before  which 
signifies  hindering  or  thwarting,  and  this  meaning  has 
finally  monopolized  the  term.  We  find  this  kind  of 
change,  again,  in  the  word  '  prove  '  (Lat.  prohare), 
which  originally  meant  '  to  test,'  a  meaning  which 
has  been  preserved  in  the  saying,  "  The  exception 
proves  the  rule."  The  specific  meaning  that  it  pos- 
sesses at  present  is  '  tested  successfully,'  or  '  tested 
and  found  reliable  ';  and  it  is  in  this  sense  that  an 
assertion  or  mathematical  theorem  is  said  to  be  proved. 
With  this  meaning  of  the  word,  however,  the  saying 
that  the  exception  proves  the  rule  is,  of  course,  pure 
nonsense. 

Thirdly,  as  the  process  of  differentiation  goes  on, 


CLASSIFICATION  AND  CLASS  NAMES        17 

the  name  may  be  retained  by  each  of  several  con- 
notations, which,  after  the  differentiation  has  been 
completed,  have  little  to  do  with  each  other.  Thus 
it  happens  that  we  speak  of  the  house  across  the  street, 
and  the  house  of  Hohenzollern ;  the  Secretary  of  State, 
and  the  President's  secretary;  his  father's  counsel, 
and  the  counsel  for  the  railway;  the  church  on  the 
corner,  and  the  Church  of  Kome,  etc.  Originally 
these  names  doubtless  betokened  some  unanalyzed  or 
imperfectly  analyzed  resemblance.  That  the  words  of 
this  class  are  very  numerous  can  easily  be  ascertained 
by  glancing  over  a  few  pages  of  any  standard  diction- 
ary. The  word  '  clerk,'  for  example,  means  "  Clerk 
in  holy  orders,  church  clerk,  town  clerk,  clerk  of 
assize,  grocer's  clerk.  In  early  English,  the  word 
meant  '  man  in  a  religious  order,  cleric,  clergyman  ' ; 
ability  to  read,  write,  and  keep  accounts  being  a 
prominent  attribute  of  the  class,  the  word  was  ex- 
tended on  this  simple  ground  till  it  has  ceased  alto- 
gether to  cover  its  original  field  except  as  a  formal 
designation."*  The  sharp  discriminations  of  mean- 
ing found  in  the  dictionary  and  in  common  usage 
point  to  an  antecedent  period  in  which  the  meanings 
were  less  clearly  differentiated.  By  some  minds  these 
distinctions  are  perhaps  not  reached  at  all.  It  is  not 
uncommon,  for  example,  to  find  that  some  people 
attribute  to  the  church  as  a  building  a  measure  of  the 
sanctity  and  divinity  which  they  ascribe  to  the  church 
as  an  institution^ 

Vagueness. — We  have  seen  that  the  use  of  meta- 
phor is  the  first  step  in  a  process  of  differentiation 

*  Minto,  Logic,  p.  85. 

f  Cf.  Jevons,  Lessons  in  Logic,  Lesson  VI. 


IS  AN  OUTLINE  OF  LOGIC 

which  has  as  its  goal  a  class  name  that  serves,  on 
tlu>  side  of  denotation,  to  point  out  a  group  of  things 
definitely  marked  off  from  other  things,  and,  on  the 
side  of  connotation,  a  group  of  attributes  that  can  be 
definitely  specified  and  enumerated.  A  word  ceases 
to  be  a  metaphor  and  becomes  a  class  name  when  it 
connotes  those  attributes  which  are  common  to  the 
different  members  of  the  class,  to  the  exclusion  of 
the  attributes  which  are  peculiar  to  individuals.  Thus 
the  word  '  ship  '  in  the  saying,  "  The  camel  is  the 
ship  of  the  desert,'  is  a  metaphor  and  not  a  class 
name,  because  the  meaning  of  the  term  is  not  con- 
fined to  the  attributes  common  to  both  vessels  and 
camels.  On  the  other  hand,  a  word  like  '  man  '  is 
a  class  name,  because  it  stands  for  certain  generic 
attributes,  apart  from  the  peculiarities  of  race,  na- 
tionality, custom,  or  occupation.  These  common  quali- 
ties, however,  may  be  '  felt  '  rather  than  distinctly 
conceived;  and  when  this  is  the  case,  when  we  are 
able  to  go  but  a  short  way  in  the  enumeration  of 
the  attributes  connoted  by  a  term,  it  is  said  to  be 
vague.  Examples  are  found  in  terms  like  '  society,' 
'  gentleman,'  '  wealth,'  '  spirit,'  and  '  culture.' 

A  term,  therefore,  is  vague  in  so  far  as  we  are 
unable  to  state  its  connotation.  So  long  as  the  term 
serves  the  purpose  for  which  it  is  intended,  the  vague- 
ness may  not  matter  a  great  deal.  We  constantly 
employ  terms  which  we  are  unable  to  define,  without 
suffering  any  particular  inconvenience  from  the  fact. 
But  this  is  not  always  the  case.  It  has  just  been 
shown  that,  as  experience  grows,  words  change  their 
meaning,  or — what  is  the  same  thing — we  change  our 
classifications.     Things  which  at  first  are  classified 


CLASSIFICATION  AND  CLASS  NAMES        19 

together  rather  promiscuously  on  the  basis  of  an  un- 
analyzed  resemblance,  tend  to  fall  into  sub-classes, 
as  was  illustrated  in  connection  with  the  terms 
'  house,'  '  secretary,'  '  counsel,'  and  '  church.'  Each 
of  these  sub-classes  involves  its  own  distinctive  prin- 
ciple of  grouping  or  point  of  resemblance,  but  until 
the  various  meanings  have  been  differentiated  from 
each  other,  these  resemblances  are  merely  '  felt.'  The 
result  of  it  all  is  that  the  term  which  covers  all 
these  sub-classes  may  mean  different  things  in  differ- 
ent contexts,  without  our  being  aware  of  the  fact. 
When  this  occurs,  confusion  and  fallacy  become  in- 
evitable. 

As  an  illustration  of  the  matter  under  discussion 
we  may  take  the  following  passage:  "  The  words 
'  nature  '  and  '  natural  '  are  constantly  bandied  about 
in  controversy  as  if  they  settled  quarrels,  whereas 
they  only  provoke  them  by  their  ambiguity.  Slavery 
has  been  condemned  as  an  '  unnatural  '  institution, 
and  has  been  defended  on  the  ground  of  the  '  natural  ' 
inferiority  of  some  races  to  others.  The  equality  of 
the  sexes  is  asserted  and  denied  on  the  ground  of 
'  nature. '  The  '  natural  '  goodness  and  the  '  natural  ' 
badness  of  mankind  have  been  maintained  with  like 
earnestness  and  sincerity.  '  To  live  according  to 
Nature  '  was  the  Stoic  formula  for  the  good  life ;  those 
Christian  theologians,  who  have  in  some  ways  most 
intellectual  and  moral  affinity  with  the  Stoics,  have 
been  those  who  have  spoken  most  strongly  about  the 
corruption  of  '  the  natural  man.'  '  Natural  religion  ' 
means  something  very  different  from  '  Nature  wor- 
ship.' '  A  natural  child  '  means  a  child  born  out  of 
wedlock ;  but  '  an  unnatural  child  '  is  not  necessarily 


20  AN  OUTLINE  OF  LOGIC 

legitimate.  '  A  state  of  nature  '  may  mean  the  ab- 
sence of  clothing;  but  such  absence  is  not  considered 
essential  to  the  possession  of  '  a  natural  manner  '  in 
society.  To  the  sentiment  that  '  Nature  is  a  holy 
thing  '  may  always  be  opposed  the  proposition  that 
1  Nature  is  a  rum  'un, '  and,  in  view  of  the  ambiguity 
of  the  term,  the  theory  of  Mr.  Squeers  is  perhaps  the 
more  easily  defensible  of  the  two. ' '  * 

A  further  illustration  of  the  same  fact  may  be 
drawn  from  the  debates  between  the  defenders  of 
'  State  Rights  '  and  the  '  advocates  of  the  national 
theory  of  government,'  concerning  the  proper  inter- 
pretation of  the  Constitution.  The  opening  words  of 
the  preamble,  "  We,  the  people  of  the  United  States, 
in  order  to  form  a  more  perfect  union, "  serve  to  show 
how  vagueness  may  be  concealed  beneath  an  appear- 
ance of  innocence  and  simplicity.  With  regard  to  this 
phrase,  J.  C.  Calhoun,  the  famous  exponent  of  state 
rights,  says,  "  The  advocates  of  the  national  theory 
of  government,  assuming  that,  '  we,  the  people/  meant 
individuals  generally,  and  not  people  as  forming 
states ;  and  that  '  United  States  '  was  used  in  a  geo- 
graphical and  not  a  political  sense,  made  out  an 
argument  of  some  plausibility,  in  favor  of  the  con- 
elusion  that  '  we,  the  people  of  the  United  States  of 
America/  meant  the  aggregate  population  of  the 
States  regarded  en  masse,  and  not  in  their  distinctive 
character  as  forming  separate  political  communities. " 
This  interpretation,  according  to  Calhoun,  is  falla- 
cious. Moreover,  "  It  could  not  have  been  intended, 
by  the  expression  in  the  preamble, — '  to  form  a  more 
perfect  union  ' — to  declare,  that  the  old  was  abolished, 
*  Ritchie,  Natural  Rights,  p.  20. 


CLASSIFICATION  AND  CLASS  NAMES        21 

and  a  new  and  more  perfect  union  established  in 
its  place ;  for  we  have  the  authority  of  the  convention 
which  formed  the  constitution,  to  prove  that  their 
object  was  to  continue  the  then  existing  union."  * 

A  word  may  be  vague  for  either  of  two  reasons: 
(a)  We  may  never  have  tried,  or  succeeded,  in  dif- 
ferentiating the  various  meanings  which  it  has  already 
acquired  (as  in  the  case  of  a  word  like  '  nature  ')  ; 
or,  (b)  A  new  situation  may  arise  to  which  the  former 
meanings  of  the  term  are  inadequate.  A  concrete 
instance  of  such  a  situation  is  furnished  in  some  inci- 
dents which  occurred  in  connection  with  a  recent  elec- 
tion for  United  States  senator.  The  national  law  pro- 
vides that  each  house  of  the  legislature  shall  vote 
separately,  and  that  "  the  person  so  voted  for  who 
receives  a  majority  of  the  whole  number  of  votes 
cast  in  each  house  "  shall  be  considered  elected.  In 
this  particular  instance  one  of  the  candidates  re- 
ceived a  majority  of  the  votes  in  the  lower  house  of 
the  legislature.  In  the  upper  house,  or  senate,  he 
polled  a  vote  of  twelve,  out  of  a  total  of  thirty-three. 
Of  these  thirty-three,  however,  there  were  sixteen  who 
voted  for  none  of  the  candidates,  but  who  merely 
voted  '  present.'  This  procedure  raised  a  difficulty, 
which  is  stated  in  a  newspaper  report  as  follows: 

"  Are  the  sixteen  senators  who  voted  '  present  '  to 
be  counted  as  '  voting  '  at  all?  If  they  are,  then 
Blank's  twelve  do  not  constitute  a  majority  of  the 
thirty-three  senators,  but  if  they  are  regarded  as 
merely  '  present,'  then  of  the  remaining  seventeen 
Blank's  twelve  are   a  majority.     Those   who  voted 

*  Calhoun,  On  the  Constitution  and  Government  of  the 
United  States. 


22  AN  OUTLINE  OF  LOGIC 

'  present  '  claim  they  actually  '  voted,'  and  that  they 
are  entitled  to  be  counted  as  actually  voting;  there- 
fore, that  Blank  failed  to  obtain  a  majority  of  the 
'  uhole  number  of  votes  cast. '  Just  there  is  the  crux 
of  the  situation.  If  these  sixteen  are  treated  as  merely 
present,  but  not  figuring  in  the  '  whole  number  of 
votes  cast,'  Blank  is  already  elected." 

The  question  thus  presented  was  not  settled  at  the 
time;  and  a  few  days  later,  when  the  legislature  met 
in  joint  session,  as  required  by  law,  a  similar  question 
arose.  There  were  124  votes  cast,  of  which  Blank 
got  62,  just  one  short  of  a  majority.  One  vote,  how- 
ever, for  Blank  had  not  been  counted,  for  the  member 
who  cast  the  vote  had  requested  leave  to  withdraw  it, 
on  the  ground  that  he  was  '  paired  '  with  another 
member.  When  he  voted  he  thought  that  this  other 
member  was  present  and  that  he  was  therefore  re- 
leased from  his  agreement;  "  but  finding  to  the  con- 
trary before  the  clerk  had  announced  the  result,  he 
asked  to  withdraw  his  vote.  The  clerk  naturally 
heeded  his  wish.  But  some  of  Blank's  supporters 
assert  that  he  was  present,  that  he  actually  voted, 
and  that  the  rules  governing  the  legislature,  or  the 
federal  law  governing  senatorial  elections  give  no 
recognition  to  '  pairs  ' ;  therefore  that  the  clerk  could 
not  cancel  the  vote  nor  could  it  be  withdrawn — that, 
in  fact,  it  stands,  thus  giving  Blank  63  out  of  125 
votes  cast,  a  majority  of  one." 

The  occurrences  just  described  tend  to  show  that 
an  element  of  vagueness  inheres  in  all  language.  Not 
only  are  we  unable  to  give  a  respectable  definition  of 
many  everyday  terms,  but,  as  we  have  just  seen,  situa- 
tions may  arise  in  which  our  previous  meanings  are 


CLASSIFICATION  AND  CLASS  NAMES        23 

inadequate.  Thus  in  order  to  determine  whether  the 
legislators  '  voted  '  or  not,  we  are  obliged  to  define, 
more  closely  than  we  have  done  before,  what  is  meant 
by  '  voting.'  Since  we  do  not  know  everything  about 
anything,  our  thinking  is  necessarily  vague  in  some 
degree,  and  as  a  consequence  our  language  is  vague. 
The  danger  of  fallacy  that  lurks  in  vague  thinking 
is  much  increased  by  the  use  of  words.  Indispensable 
as  language  is  for  the  development  of  thinking,  since 
it  furnishes  us  with  convenient  labels  or  symbols 
wherewith  to  recall  concepts  previously  formed,  it 
must  be  recognized  at  the  same  time  that  names  may 
have  the  effect  of  drawing  our  attention  away  from 
the  differences  among  things.  It  has  been  shown  that 
we  have  a  tendency  to  recognize  resemblances,  with- 
out attempting  to  analyze  them.  If  it  happens  that 
different  things  have  the  same  name,  the  name  serves 
to  call  our  attention  specifically  to  the  resemblance, 
and  in  this  way  it  decreases  the  chanc  3  that  the  differ- 
ences will  be  noticed.  We  find  the  classification  an 
accomplished  fact,  and  we  incline  to  accept  it  at  its 
face  value.  Eternal  vigilance,  therefore,  is  the  price 
of  safety  in  the  use  of  words.  To  understand  the 
deceptive  character  of  words,  however,  is  in  itself  a 
protection,  since  to  be  forewarned  is  to  be  forearmed. 
The  fallacies  that  arise  from  vague  class  names  are 
known  as  ambiguities,  which  will  be  taken  up  more 
in  detail  in  the  next  chapter. 


CHAPTER  III 
AMBIGUITY  AND  DEFINITION 

Illustrations  of  Ambiguity. — Our  study  of  class 
names  has  shown  that  vagueness  is  their  normal  state 
rather  than  the  exception.  To  render  their  meaning 
precise  usually  requires  considerable  effort,  and  even 
then  we  do  not  always  succeed.  Our  present  task 
is  to  trace  in  detail  the  way  in  which  this  vagueness 
becomes  the  source  of  ambiguity.  The  following  argu- 
ment is  a  case  in  point : 

"  The  better  the  law  in  any  state  of  society  the 
more  good  will  be  obtained  from  it,  and  from  a  pro- 
hibitory law  half  enforced  more  than  from  the  most 
stringent  license  law  enforced  to  perfection.  Besides, 
Prohibition  always  holds  up  before  the  public  mind 
the  loftiest  ideal  of  absolute  right  in  the  law.  Thus 
the  statute  book,  like  the  Bible,  becomes  an  educator, 
although  it  may  be  violated.  I  am  no  believer  in  low, 
bad  laws  because  there  is  vice  and  degradation  among 
men.  Lift  up  the  ideals.  It  is  injurious  to  society 
to  ignore  and  violate  the  laws  of  Nature  and  of  God. 
The  golden  rule  is  none  too  good  law  for  the  savage. 
God's  own  laws  being  perfect  are  most  violated,  yet 
none  of  them  have  been  repealed  on  that  account. 
They  are  not  enforced  as  well  as  the  Maine  liquor 
law,  but  the  Ten  Commandments  are  as  inflexible  as 
the  stone  text  of  the  original,  and  their  author  issues 

24 


AMBIGUITY  AND  DEFINITION  25 

no  license  even  to  those  who  pay  fees  into  the  Treasury 
of  the  Temple  itself.  It  will  only  confirm  existing 
drunken  habits  and  enable  the  devil  to  retain  his 
own,  for  us  to  adopt  his  legislation  because  we  are 
not  able  fully  to  enforce  any  other. ' '  * 

As  to  the  merits  of  the  question  at  issue  we  need 
not  stop  to  inquire.  So  far  as  we  are  concerned,  pro- 
hibition may  be  wise  or  unwise ;  our  present  business 
is  solely  with  the  reasoning  by  which  the  position 
adopted  in  the  preceding  quotation  is  defended.  Ac- 
cording to  this  reasoning,  the  objection  to  prohibition 
that  it  cannot  be  enforced  may  be  set  aside  on  the 
ground  that  the  value  of  a  law  is  determined  essen- 
tially by  the  nature  of  the  ideal  which  it  bodies  forth. 
It  is  held  that  the  value  of  a  prohibitory  law  is  no 
more  dependent  upon  the  question  of  enforcement 
than  is  the  Golden  Rule  or  the  Decalogue.  A  little 
reflection,  however,  reveals  an  important  difference, 
viz.,  the  difference  between  a  moral  law  and  a  statu- 
tory law.  Since  these  laws  resemble  each  other  in 
that  both  are  rules  of  conduct,  we  call  them  by  the  same 
name;  but  the  moral  law  includes  certain  demands, 
such  as  industrious  habits  and  the  avoidance  of  evil 
thoughts,  which  do  not  properly  fall  within  the  scope 
of  statutory  law.  We  have,  therefore,  ground  for  the 
suspicion  that  the  value  of  a  statutory  law  is  deter- 
mined by  other  considerations  besides  its  conformity 
to  the  moral  ideal.  The  result  of  this  failure  to 
recognize  any  important  difference  between  the  two 
kinds  of  law  is  the  assertion  that  what  is  true  of  some 
laws  (viz.,  moral  laws)  is  necessarily  true  of  all. 

How  readily  a  vague  term  like  '  law  '  lends  itself 
*  North  American  Review,  Vol.  147,  p.   131. 


26  AN  OUTLINE  OF  LOGIC 

to  ambiguity  may  be  further  exemplified  by  the  fol- 
lowing argument : 

"  The  existence  of  a  power  [above  nature]  is  even 
implied  in  the  phrase  '  laws  of  nature,'  constantly 
used  by  science;  for  wherever  there  is  a  law  there 
must  be  a  lawgiver,  and  the  lawgiver  must  be  pre- 
sumed capable  of  suspending  the  operation  of  law."  * 

Here  we  have  in  a  single  sentence  an  argument 
for  the  existence  of  God  and  for  the  possibility  of 
miracles.  Since  law  implies  a  lawgiver,  and  nature 
has  laws,  nature  must  have  a  lawgiver,  and  the  law- 
giver must  be  able  to  suspend  the  law  on  occasion. 
It  seems  rather  improbable  that  a  question  wrhich  has 
caused  so  much  debate  should  admit  of  a  decision  in 
such  short  order,  and  we  have  reason  to  suspect  that 
language  is  playing  us  a  trick.  The  laws  of  nature 
and  the  laws  promulgated  by  an  authority  undoubt- 
edly have  a  certain  resemblance.  What  the  nature 
of  the  resemblance  is  we  are  fortunately  not  obliged 
to  decide.  The  argument,  however,  asserts  that  the 
resemblance,  whatever  it  may  be,  includes  the  pre- 
supposition of  an  authority.  Is  this  the  case?  It 
would  rather  seem  that  at  just  this  point  an  important 
difference  exists,  a  difference  which  some  one  has  ex- 
pressed by  saying  that  law  in  the  legislative  sense  is 
a  prescription,  whereas  natural  law  is  a  description. 
Here  the  difference  is  not  between  moral  law  and 
statutory  law,  but  between  statutory  law  and  uniform 
sequence.  Owing  to  this  difference,  we  are  not  en- 
titled to  infer  that  what  is  true  of  some,  with  regard 
to  origin,  is  necessarily  true  of  all.  Whether  a  differ- 
ent line  of  reasoning  might  not  prove  that  natural 
*  Goldwin  Smith,  Guesses  at  the  Riddle  of  Existence,  p.  143. 


AMBIGUITY  AND  DEFINITION  27 

law  originates  in  God  is,  of  course,  an  entirely  differ- 
ent matter;  our  concern  at  this  moment  is  to  show 
that  the  argument  under  consideration  turns  on  an 
ambiguity. 

An  ambiguous  argument  correctly  assumes  some 
resemblance  among  the  members  of  the  class,  but  it 
mistakes  the  nature  of  the  resemblance,  and  this  is 
the  reason  why  a  statement  which  is  supposed  to  be 
true  of  all  is  true  only  of  some.  This  is  equivalent 
to  saying  that  the  class  name  has  a  special  connota- 
tion in  this  connection.  It  implies  not  merely  the 
attribute  which  is  common  to  the  whole  class,  but  also 
the  peculiarities  which  distinguish  a  certain  part  of 
the  class  from  the  rest.  Thus  when  it  is  said  that 
law  presupposes  a  lawgiver,  the  word  law  connotes 
not  only  the  attribute  of  a  certain  fixed  order,  which 
is  peculiar  to  all  forms  of  law,  but  law  in  the  special 
sense  of  a  certain  rule  of  conduct.  Unless  we  take 
it  in  this  sense,  the  statement  does  not  hold.  "We  can- 
not say  that  the  kind  of  fixed  order  possessed  by  all 
forms  of  law  necessarily  implies  a  lawgiver.  In  other 
connections,  however,  the  class  name  is  used  in  a 
sense  which  holds  for  other  members  of  the  class,  as 
when  we  speak  of  the  laws  of  nature.  Ambiguous 
terms,  therefore,  have  more  than  one  meaning,  and 
in  order  to  expose  the  fallacy  these  different  meanings 
must  be  brought  to  light.  A  rule  that  should  always 
be  observed  in  practice  is  to  substitute  other  terms  for 
those  to  which  a  suspicion  of  ambiguity  attaches  it- 
self. The  terms  so  substituted  should  aim  to  express 
the  special  connotation  in  each  case.  When  this  is 
done  the  plausibility  of  the  argument  vanishes  at  once. 
Thus,  if  we  should  say  that  law  as  a  rule  of  conduct 


28  AN  OUTLINE  OF  LOGIC 

implies  a  lawgiver,  and  that  nature  has  regular  se- 
quences, it  would  not  occur  to  any  one  to  draw  an 
inference  from  these  two  statements. 

How  readily  the  appearance  of  cogency  may  be 
dispelled  by  substituting  for  the  ambiguous  terms 
may  be  seen  in  connection  with  the  following  argu- 
ment : 

' '  My  grandmother  would  say,  for  example : '  "What- 
ever sin  is  committed  against  an  infinite  being  is  an 
infinite  evil.  Every  infinite  evil  deserves  infinite  pun- 
ishment; therefore,  every  sin  of  man  deserves  an  in- 
finite punishment.'  My  uncle  Bill,  on  the  other  side, 
would  say:  '  No  act  of  a  finite  being  can  be  infinite. 
Man  is  a  finite  being;  therefore,  no  sin  of  man  can 
be  infinite.  No  finite  evil  deserves  infinite  punish- 
ment. Man's  sins  are  finite  evils;  therefore  man's 
sins  do  not  deserve  infinite  punishment.'  When  the 
combatants  had  got  thus  far,  they  generally  looked 
at  each  other  in  silence."  * 

In  this  case  opposite  conclusions  are  reached  and 
the  honors  of  war  are  apparently  about  even.  It 
is  evident  that  everything  depends  on  the  terms  '  in- 
finite '  and  '  finite  '  which  are  used  so  freely,  but  with 
no  attempt  at  analysis;  it  being  assumed  that  their 
meaning  is  sufficiently  clear.  But  if  we  substitute  for 
the  doubtful  terms,  we  get  something  like  this  for 
the  first  argument:  "  Whatever  sin  is  committed 
against  a  being  who  is  perfect  in  power  and  knowl- 
edge and  moral  attributes,  is  an  evil  immeasurably 
great.  Every  thoroughly  malicious  evil  deserves  end- 
less punishment;  therefore  every  sin  of  man  deserves 

*  II.  B.  Stowe,  Old  Town  Folks,  quoted  by  Lafleur,  Illustra- 
tions of  Logic,  No.  107. 


AMBIGUITY  AND  DEFINITION  29 

endless  punishment. ' '  It  may  be,  of  course,  that  these 
substitutions  are  not  quite  fair  to  the  spirit  of  the 
argument.  But  it  may  be  asserted  that  no  meaning 
which  may  be  assigned  to  the  term  infinite  will  serve 
the  purpose  which  the  argument  has  in  view.  The 
same  treatment  should  be  applied  to  the  second  argu- 
ment, which  will  be  found  equally  inconclusive. 

The  Definition  of  Ambiguity. — It  has  been  shown 
how  the  same  name  may  apply  to  a  number  of  things 
which  in  some  respects  are  widely  different  from  each 
other.  Some  of  these  differences  may  be  important 
in  a  given  situation,  while  others  are  not.  If  it  is 
claimed  that  law  presupposes  a  lawgiver,  the  distinc- 
tion between  '  laws  of  the  country  '  and  '  laws  of 
nature  '  is  important,  while  the  distinction  between 
statutory  law  and  common  law  is  not.  On  the  other 
hand,  if  it  should  be  asserted  that  law  is  the  product 
of  formal  legislative  enactment,  this  latter  distinction 
becomes  important,  since  the  assertion  would  hold  only 
for  statutory  law,  common  law  being  unwritten  and 
the  product  of  custom  and  precedent. 

Ambiguity  has  to  do  with  those  distinctions  which 
are  important  for  the  time  being.  Ambiguous  terms 
are  always  vague,  but  vague  terms  are  not  necessarily 
ambiguous.  Vagueness  is,  therefore,  not  the  same 
as  ambiguity,  because  the  vagueness  may  be  unim- 
portant. '  He  goes  to  church  every  Sunday,'  '  All 
good  citizens  respect  the  law,'  and  '  Many  old  sol- 
diers are  pensioned  by  the  government,'  are  state- 
ments which  employ  vague  terms  like  '  church,' 
1  law,'  and  '  government,'  but  they  are  not  on  that 
account  ambiguous.  It  may  be  that  the  person 
who  uses  these  terms  is  unable  to  define  them,  but 


30  AN  OUTLINE  OF  LOGIC 

this  is  a  matter  of  no  concern,  provided  that  his 
meaning  is  conveyed  with  sufficient  definiteness  for 
the  purpose  in  hand.  The  illustrations  just  given 
■would  not  ordinarily  be  considered  ambiguous,  be- 
cause in  each  case  a  clue  to  the  special  meaning  is 
furnished  by  the  context,  which  shows  what  kind  of 
church,  law,  and  government  respectively  is  intended. 
Nor,  again,  are  single  words  ever  ambiguous,  even 
though  they  have  a  number  of  different  meanings. 
They  are  not  ambiguous,  for  the  reason  that  there  can 
be  no  question  which  meaning  is  the  important  one, 
since  each  term  stands  for  all  its  meanings  impartially. 
Terms  are  ambiguous  only  as  parts  of  a  statement. 
Ambiguity  may  therefore  be  defined  as  the  neglect  of 
distinctions  in  the  meaning  of  terms,  when  these  dis- 
tinctions are  important  for  the  given  occasion. 

The  Nature  and  Purpose  of  Definition. —  The 
remedy  for  ambiguity  lies  in  definition.  To  define  is 
to  point  out  the  meaning  that  is  required  for  the 
given  occasion.  According  to  an  old  rule  which  has 
come  down  through  many  centuries  of  logical  tradi- 
tion, definitions  are  to  be  framed  in  terms  of  genus 
and  differentia.  The  genus  is  the  class  of  which  the 
thing  to  be  defined  is  a  member ;  the  differentia  is  the 
character  or  group  of  characters  which  distinguish  it 
from  other  members  of  the  class.  Thus  the  genus 
of  '  horse  '  would  be  the  wider  class  '  animal  '  or 
'  vertebrate  ' ;  the  differentia  would  be  those  peculiari- 
ties which  differentiate  the  horse  from  other  animals. 
In  a  similar  way  law  might  be  defined  as  a  rule  of 
behavior  (genus),  laid  down  by  a  certain  authority 
(differentia). 

While   this   rule   is  true   enough   in  the   abstract, 


AMBIGUITY  AND  DEFINITION  31 

it  evidently  fails  to  give  us  any  indication  which 
definition  is  the  one  that  is  required  at  the  given 
moment.  The  same  genus  and  differentia  will  not 
serve  to  bring  out  the  different  meanings  of  a  given 
term.  "As  a  matter  of  fact  there  are  several 
purposes  of  definition,  several  different  reasons  why 
we  may  want  a  word's  meaning  stated;  and  among 
these  a  broad  division  into  two  main  kinds  should 
always  be  kept  in  view.  Sometimes,  in  asking  for  a 
definition  we  want  to  know  in  general  what  is  the 
meaning  of  a  word,  how  it  is  used,  or  how  it  ought 
to  be  used  in  most  of  its  possible  contexts — for  in- 
stance, what  is  the  most  widely  accepted  meaning, 
or  the  most  convenient  meaning  for  general  purposes, 
or  the  meaning  accepted  by  the  best  authorities,  or 
the  meaning  most  historically  accurate,  most  promi- 
nent at  the  time  when  the  word  was  first  invented  or 
adopted.  Sometimes,  on  the  other  hand,  none  of  these 
questions  are  asked,  but  the  questioner's  whole  desire 
is  to  discover  how  the  word  is  used  in  some  assertion 
where  he  finds  it  ambiguous,  and  so  to  get  the  am- 
biguity removed.  Both  these  processes  are  commonly 
called  definition,  and  the  information  we  get  in  answer 
to  either  kind  of  question  has  a  certain  value.  But 
there  is  a  real  difficulty  in  remembering — what  is 
evident  enough  when  we  think  about  it — that  an 
answer  which  is  valuable  for  the  former  purpose 
may  have  (on  a  particular  occasion)  not  the  smallest 
value  for  the  latter.  The  '  general  '  definition  may 
give  you  no  hint  as  to  the  way  in  which  a  particular 
assertion  is  meant  to  be  interpreted.  You  may  know 
the  general  meaning  of  a  word  and  still  find  it  am- 
biguous in  a  particular  context,  and  then,  of  course, 


32  AN  OUTLINE  OF  LOGIC 

the  best  possible  definition  of  the  former  kind  may  only- 
give  you  stale  information  and  do  nothing  towards 
removing  your  difficulty. ' '  * 

The  value  of  this  distinction  may  perhaps  be  best 
shown  by  example.  Suppose  it  should  be  argued  that 
the  evils  of  life  merit  no  consideration,  for  the  reason 
that  transitory  things  are  unimportant,  and  human 
life  as  a  whole  is  transitory.  We  may  suspect  that 
the  word  '  transitory  '  is  ambiguous  and  turn  to  the 
dictionary  for  a  definition.  There  we  find  a  general 
definition  of  this  sort :  '  existing  for  a  short  time 
only;  quickly  passing;  shortlived;  transient  '  (Stand- 
ard Dictionary).  But  this  leaves  us  just  where  we 
were,  for  the  ambiguity  reappears  in  '  short  time,' 
'  quickly  passing, '  '  shortlived, '  '  transient. '  The  dis- 
tinction that  we  need  here  is  the  distinction  between 
what  is  transitory  as  compared  with  the  length  of 
human  life  and  what  is  transitory  in  terms  of  some 
larger  standard  like  historical  or  geological  epochs. 
In  other  cases  the  standard  may  be  still  different,  as 
when  we  say  that  the  speaker's  hesitation  or  embar- 
rassment was  but  transitory.  All  are  '  quickly  pass- 
ing '  indeed ;  yet  these  different  instances  have  little 
in  common  except  the  name.  The  rule  for  framing 
definitions  gives  no  clue  as  to  the  selection  of  the 
genus  and  differentia.  The  speaker's  hesitation  must 
be  differentiated  from  events  that  endure  more  than 
a  few  moments;  the  transitory  things  of  our  experi- 
ence must  be  marked  off  from  those  which  last  months 
or  years ;  and  life  as  a  whole  must  be  contrasted  with 
things  that  endure  for  centuries.  But  this  require- 
ment can  be  discovered  only  from  the  circumstances 
*  Sidgwick,  The  Use  of  Words  in  Reasoning,  p.  42. 


AMBIGUITY  AND  DEFINITION  33 

surrounding  the  case,  i.e.,  from  the  purpose  which  the 
definition  is  to  subserve. 

Definition  and  Synonym. — The  difference  between 
a  definition  and  a  synonym  is  that  the  synonym  merely 
substitutes  another  term  which  in  this  particular  situ- 
ation is  just  as  ambiguous  as  the  one  that  it  supplants. 
'  Shortlived  '  and  '  quickly  passing,'  for  example,  are 
not  definitions  of  '  transitory,'  as  this  word  was  used 
a  short  time  ago,  but  merely  synonyms  or  synonymous 
expressions.  In  a  similar  way  we  sometimes  speak  of 
a  definition  as  '  merely  verbal. '  It  tells  us  the  general 
meaning  of  a  term,  when  what  we  wish  to  know  is 
the  meaning  that  it  has  in  some  specific  connection. 
To  quote  from  a  dictionary  when  our  task  is  to  dis- 
cover, not  a  general  but  a  specific  meaning,  is  to 
offer  a  '  verbal  '  instead  of  a  real  definition.  "  In 
the  topic,  '  Should  the  United  States  have  exclusive 
jurisdiction  over  the  Bering  Sea?  '  if  you  look  up 
'  exclusive  jurisdiction  '  in  a  dictionary  and  find  *  en- 
tire, supreme  control,'  as  its  equivalent,  how  much 
have  you  gained  in  clearness?  What  are  the  limits 
of  '  entire  control  ';  by  what  law,  common  or  inter- 
national, are  they  applied?  Just  how  much,  too,  is 
meant,  geographically,  by  'Bering  Sea  '?  Does  the 
term  in  this  case  cover  the  straits  leading  into  the 
waters  marked  on  the  maps  by  this  name  ?  Here  are 
many  questions  not  to  be  answered  offhand,  but  only 
after  careful  examination  of  the  material  on  the  ques- 
tion. ' '  * 

Application  to  Law.- — In  the  preceding  chapter  it 
appeared  that  old  and  familiar  terms  may  fail  us 
when  new  situations  arise.     If  the   situation  is  of 
*  Baker,   The  Principles  of  Argumentation,  p.   44. 


34  AN  OUTLINE  OF  LOGIC 

sueli  a  kind  as  to  require  a  new  distinction,  the  term 
becomes  ambiguous.  This  kind  of  situation  is  of  con- 
stant recurrence  in  legal  practice.  The  following  pas- 
sage from  the  circular  of  a  teachers'  agency  shows 
how  the  issue  in  a  case  may  turn  upon  the  new  in- 
terpretation that  is  given  to  a  term ;  and  incidentally 
also  how  an  innocent-looking  contract  may  be  a  snare 
for  the  unwary.  "  We  do  not  say  that  the  commission 
is  due  us  when  a  position  is  '  secured  '  through  the 
agency.  The  commission  is  not  due  us  until  you 
'  accept  '  a  position  secured  through  the  agency.  Posi- 
tions are  not  infrequently  secured  for  teachers  on 
the  strength  of  information  furnished  by  agencies  to 
the  employer,  and  sometimes  they  are  not  so  situated 
that  they  can  accept  them,  and  probably  they  do  not 
want  them.  In  cases  of  this  kind  you  would  not  be 
held  for  the  commission  by  us."  The  proper  meaning 
of  a  word  like  '  secure  '  may  on  occasion  become  a 
matter  of  serious  doubt,  and  the  outcome  of  a  case 
in  law  may,  at  best,  be  a  matter  of  conjecture. 

How  new  situations  may  require  new  interpretations 
is  suggested  rather  startlingly  by  the  following  ex- 
tracts from  a  discussion  entitled,  Trespass  on  a  Land- 
owner's Air: 

"  This  question,  which  until  recently  has  been 
purely  academic,  is  now  arising  in  connection  with 
the  probable  increased  use  of  appliances  for  aerial 
navigation.  Does  a  balloon  trespass  on  a  man's  prop- 
erty simply  by  passing  over  it?  What  is  alleged  to 
be  the  first  case  in  which  an  aeronaut  was  held  liable 
for  trespass  was  decided  in  a  London  court  on  June  8. 
While  the  defendant  was  passing  over  Priory-lane, 
Roehampton,  his  balloon  descended  and  the  grappling- 


AMBIGUITY  AND  DEFINITION  35 

iron  broke  several  telephone  wires.  The  Postmaster- 
General,  who  sued  for  the  cost  of  repairing  the  wires, 
was  held  entitled  to  judgment  for  16s. — the  amount 
of  the  damage.  Commenting  on  this,  a  writer  .  .  . 
says: 

"  '  So  long  as  the  balloon  passes  over  land  at  a 
great  height  the  rights  of  property-owners  are  not 
likely  to  be  seriously  considered.  But  the  mere  fact 
that  rights  have  never  been  enforced  does  not  prove 
that  they  do  not  exist.  Is  the  passage  of  a  balloon 
or  an  aeroplane  over  a  piece  of  land  a  trespass  in 
the  eye  of  the  law  ?  According  to  Blackstone :  ' '  Land 
hath  also,  in  its  legal  signification,  an  indefinite  ex- 
tent, upward  as  well  as  downward  "...  Applying  this 
definition  of  land,  it  is  easy  to  see  that  the  balloon 
or  aeroplane  may  pass  through  the  property  of  many 
owners  during  a  single  flight.  It  may  be  that  the 
flight  does  no  actual  damage ;  but  that  is  immaterial. 
A  man  may  walk  across  the  property  of  another  and 
do  no  damage,  yet  he  is  a  trespasser,  against  whom 
a  remedy  may  be  pursued  in  the  courts.  Again  it  is 
a  trespass  to  suspend  anything  over  a  man's  land, 
even  if  its  presence  does  him  an  infinitesimal  amount 
of  harm.' 

"  Numerous  decisions  in  regard  to  shooting  over 
a  man's  land,  without  touching  any  part  of  it,  apply 
here.  Injunctions  have  been  granted  to  prevent  such 
shooting. ' ' 

It  is  evident  that  the  connotation  of  the  word 
'  trespass  '  must  be  made  more  explicit  to  meet  the 
emergency.  Moreover,  this  is  merely  one  among  other 
possible  ambiguities.  As  the  article  concludes:  "  Con- 
siderations of  the   probable   rights  of  a  landowner 


36  AN  OUTLINE  OF  LOGIC 

against  the  aviator  naturally  direct  attention  to  the 
rights  of  one  aviator  against  another.  Who  shall 
define  what  is  negligence  in  the  management  of  an 
aeroplane?  What  is  the  rule  of  the  road  when  there 
is  no  road?  Must  a  machine  going  north  pass  over 
or  under  a  machine  going  south?  Must  a  horn  be 
carried  of  sufficient  power  to  fill  the  airy  deep  for 
miles  around  ?  All  these  questions  occur  to  the  mind : 
to  none  of  them  can  any  lawyer  give  a  satisfactory- 
reply.  ' '  * 

One  more  illustration  may  be  added  to  show  that 
the  scope  or  meaning  of  legal  terms  cannot  be  fully 
determined  in  advance  of  experience.  The  Constitu- 
tion gives  to  Congress  the  right  to  regulate  interstate 
commerce.  On  the  basis  of  this  provision  Congress 
passed,  in  1906,  what  was  known  as  the  Employers' 
Liability  Act,  which  provided  that  common  carriers 
should  be  subject  to  certain  liabilities  to  their  em- 
ployees, in  case  the  latter  were  injured  in  the  perform- 
ance of  their  duties.  Can  such  a  law  be  said  to 
1  regulate  '  commerce?  In  a  certain  sense  it  doubt- 
less can,  for  anything  that  affects  the  railroad  com- 
panies must  have  some  indirect  influence  upon  inter- 
state commerce.  But  is  the  influence  sufficiently  direct 
to  bring  this  law  within  the  spirit  of  the  Constitu- 
tional provision?  On  this  point  opinions  were  bound 
to  differ,  and  the  only  possibility  of  settling  the 
matter  lay  in  an  appeal  to  the  courts.  All  that  any 
legislative  authority  or  written  constitution  can  do 
is  to  lay  down  more  or  less  general  rules  for  procedure. 
The  import  of  the  general  rules  becomes  gradually 
clearer,  i.e.,  becomes  defined,  as  the  decisions  of  doubt- 
*Thc  Literary  Digest,  July  3,  1909,  p.  14. 


AMBIGUITY  AND  DEFINITION  37 

ful  cases  increase  in  number,  and  so  it  is  easy  to  see 
why  precedent  should  count  for  so  much  in  law. 

Ambiguities  of  the  sort  just  noticed  abound  in 
everyday  life,  as  might  be  expected.  No  matter  how 
extensive  our  knowledge,  there  is  always  a  '  twilight 
zone  '  where  it  is  difficult  to  decide  whether  or  not 
a  promise  was  really  fulfilled,  whether  a  certain 
decision  was  wise,  whether  a  certain  course  of  con- 
duct was  dignified  and  just.  In  this  region  agreement 
can  never  be  expected,  because  the  peculiarities  of 
temperament  and  training  are  in  the  last  resort  the 
dominating  factors. 


CHAPTER  IV 
SOME  SPECIAL  FORMS  OF  AMBIGUITY 

Why  Ambiguities  are  Classified. — All  ambigui- 
ties resemble  each  other  in  that  they  slur  over  some 
distinction  which  sound  reasoning  requires  to  be  made 
explicit.  This  slurring  over,  however,  may  occur  in  a 
variety  of  ways;  and  for  this  reason  many  attempts 
have  been  made  to  classify  the  different  forms  of 
ambiguity.  This  is,  of  course,  a  perfectly  legitimate 
undertaking,  but  it  should  not  be  overlooked  that  such 
classification  has  value  only  up  to  a  certain  point. 
Any  one  who  attempts  this  classification  soon  finds 
that  he  is  engaged  in  an  endless  task,  since  the  only 
limit  to  the  classification  is  his  ingenuity  in  discovering 
distinctions.  A  classification  that  is  too  elaborate  to 
be  easily  remembered  and  applied,  serves  no  useful 
purpose.  To  avoid  such  a  result  we  shall  be  content 
to  consider  a  few  of  the  more  common  types  of  am- 
biguity, so  as  to  recognize  them  more  readily  when 
they  come  our  way. 

The  Fallacy  of  Accident. —  This  fallacy  has  to  do 
with  the  interpretation  of  statements  made  by  some  one 
else.  It  is  a  fallacy  that  is  committed,  not  by  the 
person  who  makes  the  statement,  but  by  the  one 
who  construes  it.  The  source  of  the  fallacy  lies  in 
the  distinction  between  what  is  meant  and  what  is 
said;  or,  in  the  language  of  logic,  in  the  difference 
between  the  judgment  and  the  proposition.    A  judg- 

38 


SOME  SPECIAL  FORMS  OF  AMBIGUITY        39 

ment  is  an  assertion,  i.e.,  an  affirmation  or  denial  of 
an  idea;  while  a  proposition  is  a  judgment  expressed 
in  words.  It  frequently  happens  that  judgment  and 
proposition  do  not  quite  coincide.  The  proposition 
may  be  either  too  wide  or  too  metaphorical  to  be 
taken  literally;  or  it  may  permit  of  various  interpre- 
tations, if  taken  in  isolation.  What  is  really  intended 
can  often  be  determined  by  other  statements  of  the 
same  speaker  or  by  the  use  of  a  little  common  sense. 
The  fallacy  of  accident  consists  in  the  neglect  of  some 
qualification  or  limitation  which  is  left  unexpressed, 
but  which,  in  fairness,  should  be  taken  for  granted. 
As  the  name  implies,  this  fallacy  confuses  the  essen- 
tial with  the  accidental,  the  spirit  with  the  letter. 

It  has  already  been  said  that  the  failure  to  point 
out  an  important  distinction  is  not  an  ambiguity,  if 
there  is  good  reason  to  suppose  that  the  distinction 
is  recognized.  Distinctions  may  be  so  obvious  that 
they  are  taken  for  granted.  '  A  person  should  not  live 
beyond  his  income,'  does  not  necessarily  mean  that 
he  must  never  incur  obligations  which  he  is  unable 
to  meet  on  the  spot.  The  statement  holds  only  for 
a  limited  number  of  cases,  a  qualification  such  as 
'  other  things  equal,'  or  '  under  ordinary  conditions,' 
or  '  as  a  rule,'  being  implied.  Or  if  we  should  say 
that  a  certain  individual  will  succeed  in  some  under- 
taking, because  '  where  there's  a  will  there's  a  way,' 
it  is  likely  that  the  reason  which  is  assigned  requires 
closer  specification,  since  there  are  instances  in  plenty 
where  the  most  determined  will  fails  to  find  a  way. 
What  is  meant,  perhaps,  is  that  this  person  with  his 
peculiar  talents  and  under  these  particular  conditions, 
may  be  expected  to  succeed.     It  is  frequently  nee- 


40  AN  OUTLINE  OF  LOGIC 

essary  to  assume  that  the  speaker  recognizes  qualifica- 
tions of  this  kind,  at  least  in  the  sense  that  if  he 
were  questioned  regarding  the  matter,  he  would  limit 
the  statement. 

That  sweeping  statements  must  not  be  taken  too 
seriously,  is  a  fact  which  has  long  been  recognized, 
after  a  fashion,  by  common  sense.  Popular  maxims, 
for  example,  into  which  practical  experience  fre- 
quently condenses  itself,  are  not,  as  a  rule,  meant  to 
be  taken  without  qualification.  "We  are  told  that  haste 
makes  waste;  that  honesty  is  the  best  policy;  that 
larger  ships  may  venture  more,  but  smaller  barks 
should  stay  near  the  shore ;  that  early  to  bed  and  early 
to  rise,  makes  a  man  healthy  and  wealthy  and  wise. 
As  they  stand,  these  bits  of  wisdom  suggest  no  limita- 
tion to  their  scope.  The  qualifications  are  not  ap- 
pended to  the  maxims  in  the  form  of  provisos,  but 
are  expressed  in  other  maxims  which  claim  equal 
authority  with  the  first.  Haste  may  be  injudicious, 
yet  it  is  the  early  bird  that  catches  the  worm ;  honesty 
is  often  profitable,  but  we  are  reminded  that  virtue  is, 
after  all,  its  own  reward ;  small  vessels  should  be  care- 
ful, but  we  are  also  admonished  that '  faint  heart  never 
won  fair  lady  ';  and  correct  habits  of  living,  however 
commendable,  are  not  supposed  to  invalidate  the  maxim 
that  a  fool  and  his  money  are  soon  parted.  Each 
maxim  has  a  nucleus  or  core  of  truth ;  as  we  say,  there  is 
'  something  in  it  ';  but  we  are  not  sure  of  its  precise 
extent  or  of  the  conditions  under  which  it  holds  true. 
They  are  all  general,  in  the  sense  that  they  refer  to 
an  indefinite  number  of  eases;  but  they  are  not 
universal,  because  they  do  not  apply  to  each  member 
of  their  respective  classes.    Their  indefiniteness  is  due 


SOME  SPECIAL  FORMS  OF  AMBIGUITY       41 

to  the  fact  that  the  conditions  are  too  complex  to 
permit  us  to  subdivide  the  class  in  such  a  way  as  to 
mark  off  clearly  the  range  of  applicability. 

This  being  the  case,  common  sense  is  obviously  justi- 
fied in  not  attempting  to  express  itself  in  such  a  way 
that  the  range  of  application  of  every  statement  shall 
be  clear.  As  we  have  learned  before,  we  must  be 
content  with  generalities  of  undefined  range,  with 
statements  of  uncertain  import.  Unless  we  are  pre- 
pared, whether  in  speaking  or  in  listening,  to  take 
something  for  granted,  to  assume  qualifications  that 
are  not  expressed,  rational  conversation  is  out  of  the 
question.  It  is  characteristic,  however,  of  a  certain 
type  of  mind  that  it  cannot  let  these  vague  generaliza- 
tions alone.  It  undertakes  the  impossible  task  of 
specifying  the  range  of  their  application;  an  under- 
taking which  results  simply  in  an  elaboration  of  the 
obvious,  with  no  significant  limitation  of  range.  The 
following  summary  of  a  dissertation  by  a  village  wise- 
acre is  fairly  typical:  "  Impulsiveness  is  bad.  Of 
course,  there  may  be  occasions,  as  in  a  railroad  wreck, 
when  quick  action  is  desirable ;  but  a  man  must  not  be 
too  impulsive ;  he  must  not  be  impulsive  when  coolness 
and  reflection  are  required."  Precisely.  The  limita- 
tion is  so  true  as  to  be  a  truism,  which  any  average 
person  would  take  for  granted.  So  we  are  left  where 
we  began.  The  proposition  that  impulsiveness  is  bad 
is  not  absolutely  true,  nor  is  it  so  intended.  But  how 
far  it  is  true  or  what  kinds  of  impulsiveness  are  bad, 
we  know  now  as  little  as  before. 

"  When  two  minds  of  a  high  order,  interested  in 
kindred  subjects,  come  together,  their  conversation  is 
chiefly  remarkable  for  the  summariness  of  its  allusions 


42  AN  OUTLINE  OF  LOGIC 

and  the  rapidity  of  its  transitions.  Before  one  of  them 
is  half  through  a  sentence  the  other  knows  his  mean- 
ing and  replies.  Such  genial  play  with  such  massive 
materials,  such  an  easy  flashing  of  light  over  far 
perspectives,  such  careless  indifference  to  the  dust  and 
apparatus  that  ordinarily  surround  the  subject  and 
seem  to  pertain  to  its  essence,  make  these  conversations 
seem  true  feasts  for  the  gods  to  a  listener  who  is 
educated  enough  to  follow  them  at  all.  His  mental 
lungs  breathe  more  deeply,  in  an  atmosphere  more 
broad  and  vast  than  is  their  wont.  On  the  other  hand, 
the  excessive  explicitness  and  shortwindedness  of  an 
ordinary  man  are  as  wonderful  as  they  are  tedious 
to  the  man  of  genius.  But  we  need  not  go  as  far 
as  the  ways  of  genius.  Ordinary  social  intercourse 
will  do.  There  the  charm  of  conversation  is  in  direct 
proportion  to  the  possibility  of  abridgment  and  elision, 
and  in  inverse  ratio  to  the  need  of  explicit  statement. 
With  old  friends  a  word  stands  for  a  whole  story  or 
set  of  opinions.  "With  new-comers  everything  must 
be  gone  over  in  detail.  Some  persons  have  a  real 
mania  for  completeness,  they  must  express  every  step. 
They  are  the  most  intolerable  of  companions,  and  al- 
though their  mental  energy  may  in  its  way  be  very 
great,  they  always  strike  us  as  weak  and  second-rate. 
In  short,  the  essence  of  plebeianism,  that  which  sepa- 
rates vulgarity  from  aristocracy,  is  perhaps  less  a 
defect  than  an  excess,  the  constant  need  to  animadvert 
upon  matters  which  for  the  aristocratic  temperament 
do  not  exist."  * 

Having  said  this  much,  however,   in  justification 
of  common   usage,   we  may  now  urge  the   dangers 
*  James,  Psychology,  Vol.  II.,  p.  370. 


SOME  SPECIAL  FORMS  OF  AMBIGUITY        43 

that  this  usage  involves.  If  some  one  cites  one  of 
these  vague  generalizations  in  support  of  some  view 
that  he  upholds,  the  absence  of  a  qualification  may 
prevent  both  him  and  ourselves  fsom  seeing  that  he 
is  committing  a  fallacy  of  accident.  Thus  a  measure 
which  is  intended  to  correct  an  evil  may  be  opposed 
on  the  ground  that  '  men  cannot  be  made  moral  by 
legislation. '  This  contention  undoubtedly  contains  an 
element  of  truth.  However  correct  a  measure  may 
be  from  the  point  of  view  of  morality,  its  wisdom  may 
be  doubted,  if  the  moral  standard  which  it  sets  up  is 
too  greatly  divergent  from  that  of  the  people  at  large, 
or  if  the  law  cannot  be  sufficiently  enforced,  because 
it  deals  with  matters  that  are  not  a  proper  concern 
of  legislation.  But  on  the  other  hand,  it  could  hardly 
be  maintained  that  laws  have  nothing  to  do  with  public 
morality.  If  the  objection  to  the  proposed  measure 
is  to  apply,  it  must  be  shown  that  the  measure  is  of 
some  such  character  as  just  indicated.  Otherwise,  we 
merely  take  advantage  of  the  vagueness  to  assume  that 
the  case  under  discussion  falls  within  the  scope  of 
the  generalization,  i.e.,  we  take  the  statement  more 
literally  than  was  intended. 

The  manner  in  which  such  a  confusion  may  be 
made  to  serve  some  special  purpose  may  be  shown 
further  by  a  passage  from  a  lawyer's  plea  before  a 
jury: 

"  What  is  a  reasonable  doubt?  The  term  seems 
to  define  itself  in  its  own  words.  A  reasonable  doubt 
is  a  doubt  which  any  reasonable  man  may  have.  You 
are  all  reasonable  men,  and  whenever  you  doubt  you 
can  say  that  it  is  a  reasonable  doubt,  the  benefit  of 
which  the  law  says  you  must  give  to  the  defendant." 


44  AN  OUTLINE  OF  LOGIC 

"While  a  reasonable  doubt  may,  if  we  choose,  be 
described  as  '  a  doubt  which  any  reasonable  man  may 
have/  this  must  be  understood  in  the  sense  that  it 
is  the  doubt  of  a  reasonable  man,  in  so  far  as  he 
is  reasonable.  This  qualification,  however,  is  ignored 
when  it  is  asserted  that ' '  whenever  you  doubt  you  can 
say  that  it  is  a  reasonable  doubt."  The  most  rea- 
sonable of  men  may  have  unreasonable  doubts,  and 
if  such  doubts  were  to  receive  serious  consideration 
the  intention  of  the  law  would,  in  many  cases,  be  set 
at  naught. 

Essentially,  the  same  considerations  apply  to  all 
cases  in  which  a  proverb  or  maxim  is  made  to  cover 
an  individual  instance.  It  is  plain  that  a  detached 
statement  may  give  little  indication  of  its  real  mean- 
ing. We  do  not  always  say  just  what  we  mean  or 
mean  what  we  say.  How  much  scope  is  left  to  in- 
dividual interpretation  appears  rather  strikingly  in 
connection  with  the  various  constructions  that  have 
been  placed  upon  certain  passages  of  Scripture.  "  If 
thy  right  hand  offend  thee,  cut  it  off, ' '  has  occasionally 
been  taken  literally;  "  Thou  shalt  not  kill,"  has  been 
construed  in  the  sense  of  vegetarianism ;  ' '  Sell  all  that 
thou  hast  and  give  it  to  the  poor,"  has  been  regarded 
as  a  behest  to  shun  earthly  possessions;  "  Let  your 
words  be  yea,  yea,  and  nay,  nay,"  has  been  con- 
sidered a  condemnation  of  all  oaths ;  ' '  Turn  the  other 
cheek,"  has  been  understood  as  incompatible  with  go- 
ing to  war;  and  the  passage,  "  Therefore  art  thou 
inexcusable,  0  man,  whosoever  thou  art  that 
judgest, "  was  once  cited,  some  years  ago,  as  the 
basis  of  a  conscientious  scruple  against  service  on 
a  jury. 


SOME  SPECIAL  FORMS  OF  AMBIGUITY        45 

Absolute  and  Relative  Terms. — A  second  form  of 
ambiguity  we  may  call  for  convenience  the  fallacy  of 
relative  terms.  There  are  many  terms  like  father 
and  son,  husband  and  wife,  landlord  and  tenant,  host 
and  guest,  which  derive  their  meaning  from  their 
relations  to  each  other,  and  which  reveal  their  char- 
acter of  relativity  by  the  way  they  go  in  pairs.  Such 
pairs  are  known  as  correlative  terms.  But  there  are 
other  terms  which,  though  equally  relative,  conceal 
their  true  nature  much  more  effectively,  and  so  may 
become  the  source  of  ambiguity.  Words  like  '  pov- 
erty,' 'wealth,'  'luxury,'  and  'rapidity'  are  ex- 
amples. We  tend  to  think  of  these  as  '  absolute  ' 
terms,  i.e.,  as  terms  which  have  a  more  or  less  fixed 
and  independent  meaning,  like  '  gold,'  or  '  planet,' 
or  '  tree. '  As  a  matter  of  fact,  however,  they  likewise 
derive  their  meaning  from  certain  relations,  or  from 
a  comparison  which  they  presuppose.  For  this  reason 
their  import  changes  with  a  change  in  the  things  com- 
pared. A  relative  term,  therefore,  is  a  term  that 
implies  a  reference  to  a  variable  standard.  What  is 
wealth  for  one  person  is  not  necessarily  such  for 
another;  and  what  is  luxury  for  one  generation  may 
be  classed  with  the  necessaries  of  life  by  the  next.  A 
1  comfortable  income  '  is  not  a  fixed  quantity,  but 
is  a  name  for  a  certain  relation  between  our  actual 
income  and  our  demands  and  desires.  This  fact  is 
recognized  in  the  humorous  suggestion  that  a  com- 
fortable income  is  '  a  little  more  than  we  have.'  If, 
however,  this  dependence  on  a  varying  standard  is 
overlooked,  the  door  is  opened  to  ambiguity.  Thus 
the  previous  argument,  to  the  effect  that  the  evils 
of    life,    being    transitory,    do    not    require    serious 


46  AN  OUTLINE  OF  LOGIC 

thought,  turns  on  the  ambiguity  of  the  word  £  transi- 
tory,' which  is  a  purely  relative  term,  i.e.,  implies 
different  standards  in  different  connections. 

To  recognize  and  point  out  this  character  of  rela- 
tivity may  on  occasion  serve  to  forestall  much  fruit- 
less argument.  For  example,  the  question  may  be 
asked,  ' '  Are  the  people  of  the  present  day  more  moral 
than  those  of  the  past?  "  Before  we  undertake  to 
express  an  opinion  we  should  ascertain  what  is  meant 
by  '  more  moral.'  To  judge  the  past  by  present-day 
standards  is  one  thing;  to  judge  it  by  its  own  stand- 
ards is  quite  another.  Again,  the  question  may  be 
raised  whether  or  not  students  who  go  into  business 
are  as  a  rule  more  capable  than  those  who  adopt 
the  profession  of  teaching.  Discussions  of  a  question 
like  this  are  prone  to  overlook  the  relativity  of  a 
phrase  like  '  more  capable. '  Until  we  specify  whether 
we  mean  '  capable  for  business  '  or  '  capable  for  teach- 
ing '  or  some  other  form  of  capableness,  argument 
is  likely  to  be  futile. 

Parallel  cases  are  found  in  questions  like,  "  Which 
are  the  hundred  best  books?  "  or  "  Who  are  the  ten 
greatest  Americans?  " — questions  that  cannot  be 
answered  until  we  know  by  what  standards  our  judg- 
ments are  to  be  determined.  Literary  excellence  is 
one  thing,  scientific  is  another,  and  moral  excellence 
is  a  third.  The  term  '  drunk  '  is  another  instance. 
Although  easily  overlooked  in  everyday  life,  the  rela- 
tivity of  this  term  is  well  known  in  police  courts. 
It  is  applied  to  widely  different  forms  or  stages  of 
inebriety,  the  range  of  which  is  indicated  by  the 
classification  of  aa  ingenious  lawyer  who  distinguished 
the  different  stages  of  drunkenness  as  the  jocose,  the 


SOME  SPECIAL  FORMS  OF  AMBIGUITY        47 

verbose,  the  bellicose,  and  the  comatose.  These  differ- 
ent stages  may  or  may  not  be  all  included.  An  editor 
writes  thus  regarding  "  Standards  of  Drunkenness  ": 

' '  A  correspondent  of  one  of  the  Toronto  newspapers 
points  out  that  on  Christmas  day  in  Toronto,  which 
has  150  places  to  sell  liquor,  there  were  109  persons 
arrested  for  drunkenness,  while  in  Buffalo,  which  has 
over  3,000  barrooms,  there  were  only  thirty-nine  ar- 
rests. The  intention  was  to  prove  that  the  number 
of  licensed  places  has  no  effect  upon  the  amount  of 
drunkenness.  It  cannot  be  accepted  as  conclusive 
evidence,  for  the  police  standards  of  what  constitutes 
drunkenness  may  differ  in  the  two  cities.  In  Buffalo 
the  citizen  who  confines  himself  to  getting  drunk  is 
probably  allowed  to  go  as  soon  as  he  is  sober,  without 
a  charge  being  entered  against  him,  while  in  Toronto 
he  is  fined.  There  is  no  poorer  standard  of  estimating 
the  sobriety  of  a  city's  population  than  by  its  con- 
victions for  drunkenness." 

Concrete  and  Abstract  Terms. — The  confusion  of 
concrete  and  abstract  is  a  form  of  ambiguity  that 
has  been  the  source  of  much  trouble.  We  may  dis- 
tinguish most  conveniently  between  concrete  and  ab- 
stract terms  by  saying  that  concrete  terms  are  the 
names  of  things,  while  abstract  terms  are  concerned 
with  attributes.  The  term  attribute  is  here  used  as  in- 
clusive of  all  the  qualities,  relations,  and  actions  per- 
taining to  things.  It  is  a  peculiarity  of  abstract  terms 
that  they  can  be  used  without  reference  to  the  subjects 
which  possess  the  attributes  designated  by  them.  Thus 
we  can  speak  of  squareness  or  redness,  without  mention 
of  the  things  to  which  these  attributes  belong.  Such 
terms  tend  to  divert  our  attention  from  reference  to 


48  AN  OUTLINE  OF  LOGIC 

things,  and  for  this  reason  they  are  called  abstract. 
Judged  by  this  test,  adjectives  and  verbs,  as  used 
in  propositions,  are  always  concrete,  since  they  point 
out  the  possessors  of  the  attributes  indicated  by  them. 
If  we  say  '  the  horse  runs,'  or  '  the  horse  is  black,' 
our  language  is  concrete;  but  if  we  wish  to  speak  of 
the  attributes  indicated  by  '  runs  '  and  '  black,'  with- 
out reference  to  the  horse,  we  are  obliged  to  employ 
nouns,  such  as  '  running  '  and  '  blackness.'  Abstract 
terms,  then,  are  names  which  designate  attributes  and 
which  function  as  nouns. 

Since  attributes  may  be  mentioned  without  refer- 
ence to  the  subjects  or  things  to  which  they  belong, 
abstract  terms  have  a  certain  resemblance  to  indi- 
vidual or  proper  names.  We  speak  of  '  virtue  '  and 
'  justice,'  for  example,  in  much  the  same  way  that 
we  speak  of  the  Japanese  navy  or  John  Smith.  Now 
if  we  take  no  pains  to  bear  in  mind  their  true  char- 
acter, these  abstract  terms  may  on  occasion  mas- 
querade as  the  names  of  things,  and  perhaps  even 
assume  the  dignity  of  a  capitalized  initial,  as  in, 
"  We  come  down  then,  finally,  to  Force  as  the  ultimate 
of  ultimates. ' '  *  The  fallacy  that  is  committed  when 
we  mistake  the  character  of  abstractions  in  this  way, 
may  be  called  indifferently  the  fallacy  of  abstract 
terms,  the  fallacy  of  confusing  the  abstract  and  the 
concrete,  or  the  fallacy  of  hypostatization.  This  error 
is  much  more  frequent  than  we  should  naturally  sup- 
pose. Many  persons,  for  instance,  would  consider  it 
a  sufficient  explanation  of  the  movements  of  raindrops 
to  say  that  gravitation  causes  them  to  fall.  But  if 
we  remember  that  gravitation  is  the  name  of  an  at- 
*  Spencer,  First  Principles,  Part  II.,  Chapter  III. 


SOME  SPECIAL  FORMS  OF  AMBIGUITY        49 

tribute,  we  are  enabled  to  see  that  the  reference  to 
gravitation  means  merely  that  raindrops  belong  to 
the  class  of  gravitating  bodies.  Why  they  gravitate 
is  as  much  a  problem  as  it  was  before.  The  semblance 
of  explanation  arises  from  the  fact  that  we  hold  the 
attribute  '  gravitation  '  apart  from  the  objects  to 
which  it  belongs  and  treat  it  as  though  it  were  some 
sort  of  entity  endowed  with  power  to  act. 

Our  everyday  use  of  such  terms  as  '  conscience,' 
'  memory,'  and  '  will,'  shows  further  how  ingrained 
is  this  habit  of  treating  abstractions  as  though  they 
were  independent  things.  In  reality  these  terms  are 
the  names  of  attributes.  It  is  not  uncommon,  however, 
to  find  that  conscience,  for  example,  is  conceived,  in  a 
vague  fashion,  as  though  it  were  some  kind  of  thing, 
inhabiting  the  inmost  recesses  of  the  soul  and  per- 
forming the  functions  of  an  oracle.  Similarly, 
there  is  no  separate  thing  called  memory  or  will, 
but  only  different  instances  of  remembering  and  will- 
ing. Sometimes  abstractions  are  used  to  back  up  be- 
liefs which  we  are  predisposed  to  accept.  A  man  who 
has  committed  theft  may  argue  that  the  world  owes 
him  a  living;  the  precise  meaning  of  which  is  not 
so  apparent,  when  we  try  to  make  clear  what  is  meant 
by  '  world.'  Or  a  man  who  is  unwilling  to  make 
sacrifices  in  order  to  promote  the  public  welfare,  may 
insist  that  the  evils  which  are  causing  concern  will 
disappear  of  themselves  in  the  course  of  progress,  as 
though  progress  were  a  distinct  sort  of  agency,  and 
all  we  need  to  do  is  to  sit  down  and  wait  while  '  prog- 
ress,' like  the  Brownies  or  the  '  Gold  Dust  Twins,' 
does  our  work.  Or  again,  the  sentiment  that  "  a  cor- 
poration has  no  soul  ' '  may  sometimes  seem  tc  an  indi- 


50  AN  OUTLINE  OF  LOGIC 

vidual  to  justify  a  certain  act,  such  as  failure  to  pay 
for  transportation,  which  would  not  be  thought  of  if 
the  other  party  concerned  were  the  driver  of  a  hack. 

It  is  perhaps  worth  while  to  guard  against  the 
inference  that  the  use  of  abstract  terms  is  objection- 
able on  all  occasions.  As  a  matter  of  fact,  their  ab- 
stract character  is  frequently  their  chief  merit,  since 
it  simplifies  thought  and  speech.  Their  abstractness 
becomes  a  defect  only  when  there  is  danger  of  con- 
fusion. "Whenever  this  occurs,  the  remedy  applied  to 
other  forms  of  ambiguity  is  always  to  be  recommended, 
viz.,  the  substitution  of  other  terms  for  those  which 
are  under  suspicion.  In  the  present  case  the  sub- 
stitution should  be  of  such  a  kind  as  to  indicate  the 
reference  that  the  abstract  term  implies,  i.e.,  it  should 
point  out  the  subject  to  which  the  attribute  belongs. 
This  subject  may  be  either  a  thing  or  another  attribute. 
Instead  of  '  truth, '  for  example,  we  should  say  '  truth- 
ful person  '  or  '  truthful  statement,'  or  whatever  the 
meaning  may  happen  to  be;  for  '  gravitation  '  we 
should  substitute  '  gravitating  bodies,'  and  so  on.  In 
short,  if  there  is  ground  for  suspicion,  the  abstract 
term  should  be  used  as  an  adjective,  and  not  as  a 
noun.  Under  this  treatment  statements  which  seem 
significant  and  even  profound,  not  infrequently 
dwindle  down  to  a  mass  of  verbiage.  The  reader  can 
easily  ascertain  this  for  himself  by  making  the  proper 
substitutions  in  the  following  extract  from  a  circular 
of  healing:  "  You  have  believed  a  lie  that  you  can- 
not get  well.  The  truth  will  make  you  free.  Love 
Nature.  She  is  gentle  and  holy.  To  obey  her  is  to 
live.  .  .  .  Animals  respond  quickly  to  my  vibrations 
because  they  are  near  to  nature's  heart." 


CHAPTER  V 

THE  NATURE  AND  THE  INTERPRETATION 
OF  PROPOSITIONS 

Our  chief  interest  in  the  preceding  chapters  has 
been  the  nature  of  terms  in  their  relation  to  ambiguity. 
It  has  appeared  that  ambiguity  consists  in  the  neglect 
of  distinctions  which  are  required  in  the  given  situa- 
tion. As  a  rule,  ambiguity  means  that  a  statement 
which  holds  good  for  some  members  of  a  class  is  made 
to  apply  to  other  members  as  well.  In  other  words, 
our  discussion  has  been  confined,  in  the  main,  to 
fallacies.  We  have  not  yet  raised  the  question  what 
the  relation  of  classes  must  be  to  each  other  in  order 
to  make  correct  inferences  possible.  The  traditional 
doctrine  which  sets  forth  the  principles  of  this  rela- 
tionship is  known  as  the  doctrine  of  the  syllogism. 

The  syllogism,  which  was  first  formulated  by  Aris- 
totle and  which  was  brought  to  a  high  degree  of  per- 
fection during  the  Middle  Ages,  is  of  considerable 
interest,  owing  to  the  great  importance  that  was 
attached  to  it.  This  attitude,  however,  has  under- 
gone a  change,  and  opinions  as  to  the  value  of  the 
syllogism  are  divided.  But  whether  its  value  be  great 
or  small,  it  is  of  sufficient  importance,  both  historically 
and  intrinsically,  to  warrant  some  attention.  The 
character  of  the  syllogism  will  be  taken  up  in  detail 

51 


52  AN  OUTLINE  OF  LOGIC 

in  succeeding  chapters.  Since  the  syllogism  is  some- 
what technical,  the  present  chapter  must  be  devoted 
to  a  discussion  of  propositions  from  the  standpoint 
of  syllogistic  logic.  The  special  bearing  of  this  dis- 
cussion will  appear  at  a  later  time. 

Judgment  and  Proposition. — The  first  distinction 
that  requires  our  notice  is  the  distinction  between 
judgment  and  proposition.  As  was  stated  previously, 
a  judgment  is  a  mental  assertion  of  something  as  true 
or  untrue,  while  a  proposition  is  the  expression  of  the 
judgment  in  words.  A  proposition,  therefore,  is  a 
sentence.  Not  all  sentences,  however,  are  propositions. 
Interrogations,  for  example,  and  exclamations  are  not 
propositions,  because  they  do  not  express  judgments 
in  any  direct  way.  Moreover,  sentences  which  are 
the  direct  expression  of  a  judgment  frequently  require 
verbal  changes  in  order  to  reduce  them  to  '  logical 
form.'  By  logical  form  is  meant  that  the  proposition 
in  question  possesses  two  terms  and  a  copula  or 
connecting  link.  The  terms  are  the  subject  term  and 
the  predicate  term  respectively;  the  copula  is  some 
form  of  the  verb  '  to  be.'  Thus  the  proposition,  '  All 
Presidents  have  great  responsibilities,'  when  reduced 
to  logical  form,  becomes,  '  All  Presidents  are  persons 
who  have  great  responsibilities.'  In  this  latter  propo- 
sition '  Presidents  '  is  the  subject  term,  '  are'  is  the 
copula,  and  '  persons  who  have  great  responsibilities  ' 
is  the  predicate  term.  This  form  sometimes  gives  a 
stilted  appearance  to  a  proposition,  as,  e.g.,  when 
'  all  the  papers  published  the  event  '  is  changed  to, 
'  all  the  papers  are  things  which  published  the  event  ' ; 
but  its  convenience  for  the  purpose  of  the  syllogism 
will  soon  become  apparent. 


THE  NATURE  OF  PROPOSITIONS  53 

Categorical    and    Conditional    Propositions. — A 

proposition  is  said  to  be  categorical  if  it  makes  an 
assertion  without  condition  or  alternative.  '  He  went 
to  Boston,'  and  '  It  will  rain  before  night,'  are  ex- 
amples. On  the  other  hand,  conditional  propositions 
make  assertions  that  are  true  only  indirectly,  i.e., 
they  assert  something  to  be  true,  provided  something 
else  is  also  true;  or,  to  put  it  still  differently,  they 
assert  something  as  conditionally  true. 

Of  these  conditional  propositions  there  are  two 
kinds,  the  hypothetical  and  the  disjunctive.  The 
hypothetical  proposition  expresses  a  condition  and  a 
result  directly,  such  as  '  If  he  comes,  there  will  be 
trouble.'  In  the  case  of  disjunctive  propositions,  the 
conditional  character  takes  a  different  form.  This 
character  consists  in  the  fact  that  one  or  the  other 
of  two  or  more  specified  alternatives  is  asserted  to  be 
true,  as,  e.g., '  He  will  either  come  or  send  a  representa- 
tive.' The  assertion  of  these  alternatives  is  not  made 
directly,  but  each  alternative  is  conditioned,  as  to  its 
truth  or  untruth,  by  the  untruth  or  truth  of  the  other. 
As  will  appear  later  on,  the  distinction  between 
categorical  and  conditional  propositions  corresponds 
to  a  distinction  between  two  kinds  of  syllogism.  For 
the  present  we  shall  confine  our  attention  to  the 
categorical  proposition  and  to  the  kind  of  syllogism 
for  which  the  categorical  proposition  furnishes  the 
basis. 

The  Quality  and  Quantity  of  Propositions. — By 
the  quality  of  a  proposition  is  meant  its  character 
as  affirmative  or  negative.  An  affirmative  proposition 
asserts  that  something  is  true  of  the  subject  named, 
e.g., '  America  was  discovered  in  1492. '    In  a  negative 


54  AN  OUTLINE  OF  LOGIC 

proposition  something  is  denied  of  the  subject,  as  in, 
1  The  revolution  was  not  successful. '  The  quantity  of 
a  proposition,  on  the  other  hand,  depends  upon  the 
extension  of  the  subject  term.  If  the  proposition  con- 
cerns the  entire  class  pointed  out  by  the  subject 
term,  e.g.,  '  all  trespassers  will  be  prosecuted,'  the 
proposition  is  said  to  be  universal;  if  it  concerns  only 
some  members  of  that  class,  as  in,  '  Some  men  have 
greatness  thrust  upon  them,'  it  is  called  particular. 
Propositions  which  refer  to  a  single  person  or  thing, 
as  '  Socrates  was  a  Greek,'  or  '  the  earth  is  round,' 
are  sometimes  called  singular  or  individual  proposi- 
tions. For  syllogistic  purposes,  however,  such  proposi- 
tions are  of  the  same  kind  as  universal  propositions. 
Both  refer  to  an  entire  class,  but  in  the  case  of 
individual  propositions  the  class  happens  to  contain 
only  a  single  member. 

Propositions  which  are  of  indefinite  application,  of 
the  sort  typified  in  popular  maxims,  are  from  the 
present  point  of  view  classed  as  particular  proposi- 
tions. From  the  standpoint  of  the  syllogism  the 
distinction  between  the  universal  and  ttie  general  is 
not  recognized,  but  all  propositions  that  do  not  apply 
to  an  entire  class  are  classified  as  particular  proposi- 
tions. Finally,  it  must  be  added  that  propositions 
sometimes  show  a  discrepancy  between  form  and  mean- 
ing, with  regard  to  both  quantity  and  quality.  '  All 
is  not  gold  that  glitters  '  is  universal  in  form,  but 
particular  in  meaning,  the  meaning  being,  '  some 
things  that  glitter  are  not  gold.'  On  the  other  hand, 
propositions  beginning  with  '  only  '  or  '  none  but  ' 
are  particular  in  form  but  universal  in  meaning.  Thus 
'  only  lawyers  are  admitted  '  means,  not  merely  that 


THE  NATURE  OF  PROPOSITIONS  55 

rjomc  lawyers  are  admitted,  but  that  all  who  are 
admitted  are  lawyers.  As  to  quality,  '  few  escaped  ' 
means  that  most  did  not  escape ;  and  '  none  but  friends 
were  present,'  means  that  all  who  were  present  were 
friends. 

We  have  seen  that  propositions  may  be  either  af- 
firmative or  negative  as  to  quality,  and  either  universal 
or  particular  as  to  quantity.  We  thus  have  four 
possible  kinds  of  propositions,  which  may  be  repre- 
sented by  the  letters  A,  E,  I,  and  0.  A  and  I — 
taken  from  the  word  affirmo — stand  for  affirmative 
propositions;  while  E  and  0 — from  nego — stand  for 
negative  propositions.  These  four  forms  are  as 
follows : 

( Affirmative : 
Universal  |Negative. 

( Affirmative : 
Particular  jNegatiye. 

The  Distribution  of  Terms. — If  a  proposition 
makes  an  assertion  about  an  entire  class,  the  term 
which  designates  that  class  is  said  to  be  distributed, 
whereas  if  the  assertion  refers  to  some  members  of 
the  class  only,  it  is  undistributed.  It  should  be  noted 
that  the  distinction  between  universal  and  particular 
concerns  propositions,  while  the  distinction  between 
distributed  and  undistributed  has  to  do  with  terms. 
Thus  a  proposition  may  contain  both  a  distributed 
and  an  undistributed  term.  For  example,  in  proposi- 
tion A,  '  All  men  are  fallible,'  the  subject  term  '  men  ' 
is  distributed,  because  something  is  said  of  all  men; 
whereas   the   predicate   term   '  fallible  '   is   not   dis- 


All  S  is  P. 

A 

No    S   is   P. 

E 

Some  S  is  P. 

I 

Some  S  is  not  P. 

0 

56  AN  OUTLINE  OF  LOGIC 

tributed,  since  nothing  is  said  about  all  fallible  beings. 
In  proposition  I,  '  Some  men  are  fallible,'  neither 
term  is  distributed.  On  the  other  hand,  proposition 
E,  '  No  men  are  infallible,'  distributes  both  terms, 
for  it  tells  us  something  about  all  men,  viz.,  that 
they  all  fall  outside  the  class  of  infallible  beings,  and 
with  regard  to  infallible  beings  it  informs  us  that 
they  all  fall  outside  the  class  of  men.  Lastly,  proposi- 
tion 0,  '  Some  men  are  not  infallible,'  does  not  dis- 
tribute its  subject,  since  it  speaks  of  some  men  only ; 
but  it  does  distribute  its  predicate,  because  it  assures 
us  that  the  entire  class  of  infallible  beings  falls  out- 
side of  some  men.  This  may  be  stated  less  artificially 
if  we  say  that  in  order  to  make  the  assertion,  '  Some 
men  are  not  infallible,'  we  must  know  enough  about 
the  class  of  infallible  beings  to  feel  sure  that  none 
of  them  are  identical  with  some  men.  In  general 
we  may  say  that  negative  propositions  always  dis- 
tribute their  predicates;  whereas  affirmative  proposi- 
tions do  not  distribute  their  predicates. 

The  Obversion  and  Conversion  of  Propositions.— 
The  processes  of  obversion  and  conversion  require  us 
to  recall  the  distinction  between  the  judgment  and 
the  proposition.  It  appeared  in  connection  with  our 
study  of  the  fallacy  of  accident  that  the  two  are  not 
coincident.  A  proposition  is,  in  fact,  but  one  of  the 
various  possible  ways  in  which  the  corresponding  judg- 
ment might  be  expressed.  The  assertion  embodied 
in  the  proposition,  '  The  book  is  on  the  table,'  also 
means  that  the  table  is  under  the  book,  although 
the  proposition  does  not  provide  for  this  aspect  of  the 
case.  Similarly,  if  A  is  east  of  B,  then  B  is  west 
of  A;  if  John  is  the  son  of  James,  then  James  is 


THE  NATURE  OF  PROPOSITIONS  57 

the  father  of  John;  if  all  Presidents  are  native-born 
citizens,  then  some  native-born  citizens  are  Presidents, 
and  there  are  no  Presidents  who  are  not  native-born, 
and  no  persons  not  native-born  who  are  President; 
if  William  is  riding  the  horse  on  the  street,  then  the 
horse  is  being  ridden  by  William,  and  the  street  is 
the  place  where  the  riding  is  taking  place.  Even  a 
proposition  like,  '  it  rains,'  may  be  changed  and  ren- 
dered, '  the  rain  is  falling.'  Every  fact  that  is  as- 
serted is  more  or  less  complex,  and  the  proposition 
may,  therefore,  be  varied  so  as  to  bring  out  or 
emphasize  one  element  rather  than  another,  although 
all  are  involved. 

What  variations  are  possible  in  any  given  case  de- 
pends upon  the  nature  of  the  fact  concerned  and  can- 
not be  completely  determined  in  advance.  There  are, 
however,  two  forms  of  variation  that  can  be  studied 
independently  of  any  subject-matter.  These  two 
forms  are  known  as  obversion  and  conversion. 

01) version  is  a  name  for  the  process  by  which  a 
proposition  undergoes  a  change  in  its  quality,  i.e.,  a 
change  from  affirmative  to  negative  or  from  negative 
to  affirmative,  without  any  change  in  its  meaning. 
This  occurs,  for  example,  when  a  proposition  like,  '  all 
men  are  fallible,'  is  changed  to,  '  no  men  are  infalli- 
ble, '  or  when  we  change  '  no  foreign-born  are  eligible  ' 
to  '  all  foreign-born  are  ineligible.'  The  principle  of 
obversion  is  that  instead  of  affirming  a  predicate  as 
true  of  a  subject,  we  may  deny  its  negative;  and 
instead  of  denying  the  predicate  we  may  affirm  its 
negative.  To  exemplify  this  process,  let  us  take  the 
proposition,  '  All  the  buildings  suffered  damage.' 
When  reduced  to  logical  form  this  proposition  be- 


5S  AN  OUTLINE  OF  LOGIC 

comes,  '  All  the  buildings  are  structures  that  suf- 
fered damage.'  The  negative  of  this  predicate  is, 
1  structures  that  did  not  suffer  damage.'  Denying 
this  negative  we  have,  '  The  buildings  are  not  struct- 
ures that  did  not  suffer  damage,'  or  '  None  of  the 
buildings  are  structures  that  did  not  suffer  damage.' 

If  the  proposition  to  be  obverted  is  negative,  we 
take  the  negative  of  the  original  predicate  and  affirm 
it  of  the  original  subject.  To  illustrate  this,  let  us 
first  expand  the  proposition,  l  No  Presidents  are  care- 
free,'  into,  '  No  Presidents  are  persons  who  are  care- 
free.' The  negative  of  this  predicate  is  '  persons  who 
are  not  care-free.'  This  negative  must  be  affirmed  of 
the  subject '  Presidents  '  and  we  have,  '  All  Presidents 
are  persons  who  are  not  care-free,'  which  is  the 
obverse  of  the  original  negative  proposition.  The 
process  of  obverting  the  statement,  '  Some  planets  are 
not  inhabited,'  may  be  traced  thus:  The  original 
negative  proposition  may  be  expanded  into,  '  Some 
planets  are  not( heavenly  bodies  which  are  inhabited./ 
The  negative  of  the  predicate  is,  '  heavenly  bodies 
which  are  not  inhabited.'  According  to  the  rule  laid 
down  in  the  second  part  of  the  principle  for  obversion, 
we  must  now  take  this  negative  of  the  original  predi- 
cate and  affirm  it  of  the  original  subject.  As  a  result 
we  have,  '  Some  planets  arefheavenly  bodies  which 
are  not  inhabited./  By  obverting  this  latter  proposi- 
tion once  more,  we  get  back  to  the  original  form, 
viz.,  '  Some  planets  are  not  heavenly  bodies  which  are 
inhabited,'  or,  '  Some  planets  are  not  inhabited.' 

Conversion  means  a  change  in  the  form  of  a  proposi- 
tion whereby  the  subject  term  and  the  predicate  term 
exchange  places  with  each  other,  but  without  going  be- 


THE  NATURE  OF  PROPOSITIONS  59 

yond  the  meaning  of  the  proposition.  Thus  the 
proposition,  '  Some  Americans  are  inventors,'  may  be 
changed  to,  '  Some  inventors  are  Americans. '  In  this 
particular  case  the  process  is  extremely  simple,  but  this 
is  not  always  the  case.  Conversion  may  be  of  three 
kinds:  (a)  Simple  conversion;  (b)  Conversion  by 
limitation  or  per  accidens;  and  (c)  Conversion  by 
contraposition.  These  different  forms  result  from  the 
fact  that,  according  to  the  rule  which  governs  con- 
version, no  term  which  is  undistributed  in  the  original 
proposition  may  be  distributed  in  the  new  proposition 
which  is  obtained  as  a  result  of  the  conversion. 

Of  these  three  forms  the  first,  viz.,  simple  conver- 
sion, is  illustrated  in  the  change  of  '  Some  Americans 
are  inventors  '  to  '  Some  inventors  are  Americans  ' 
(Proposition  I).  The  terms  involved  are  undis- 
tributed in  the  second  proposition  as  well  as  in  the 
first.  Proposition  E,  '  No  men  are  quadrupeds,'  may 
likewise  be  converted  simply.  In  the  resulting  propo- 
sition, '  No  quadrupeds  are  men,'  both  terms  are  dis- 
tributed, but  since  they  were  both  distributed  in  the 
original  proposition,  the  rule  is  not  violated.  In  order, 
however,  to  convert  proposition  A,  '  All  men  are 
animals,'  we  must  convert  by  limitation.  We  cannot 
say,  '  All  animals  are  men,'  but  '  Some  animals  are 
men,'  because  the  terms  '  animals  '  is  undistributed 
in  the  original  proposition.  In  this  form  of  conversion 
proposition  A  is  changed  to  proposition  I.  We  change 
from  a  universal  to  a  particular  proposition,  and  for 
this  reason  the  process  is  called  conversion  by  limita- 
tion. "  '  Brethren,'  said  Parson  Strong,  of  Hartford, 
preaching  a  Connecticut  election  sermon,  in  high  party 
times,  some  fifty  years  ago,  '  it  has  been  charged  that 


60  AN  OUTLINE  OF  LOGIC 

I  have  said  every  Democrat  is  a  horse-thief.  I  never 
did.  "What  I  did  say  is  only  that  every  horse-thief  is 
a  Democrat,  and  that  I  can  prove.'  "  * 

The  most  complex  form  of  the  three  is  conversion 
by  contraposition.  Proposition  0,  '  Some  men  are  not 
quadrupeds,'  cannot  be  converted  simply  to  '  some 
quadrupeds  are  not  men, '  for  the  proposition  obtained 
by  conversion  distributes  the  term  '  man,'  which  was 
not  distributed  in  the  original  proposition.  Both 
propositions  happen  to  be  true,  but  they  are  not 
equivalent  to  each  other.  This  appears  if  we  substitute 
as  a  parallel  case,  '  Some  men  are  not  Presidents, '  and 
convert  it  to  '  Some  Presidents  are  not  men. '  The  only 
way  in  which  the  conversion  of  proposition  0  can 
be  accomplished  is  by  first  obverting  it  and  then  con- 
verting the  result.  '  Some  men  are  not  quadrupeds  ' 
then  becomes,  first,  '  Some  men  are  beings  that  are 
not  quadrupeds,'  and  this  in  turn  gives  us,  by  con- 
version, '  Some  beings  that  are  not  quadrupeds  are 
men.'  This  process  is  called  conversion  by  contra- 
position. 

False  Ob  version.— In  true  obversion  the  negative 
(i.e.,  the  contradictory)  of  the  original  predicate  is 
affirmed  or  denied  respectively  of  the  original  subject. 
In  such  obversion  the  meaning  remains  the  same,  for 
the  reason  that  two  negatives  constitute  an  affirmative. 
We  may  either  affirm  a  predicate  of  a  subject  or 
deny  its  negative  of  the  same  subject,  as  we  please. 
"We  cannot,  however,  take  the  same  liberties  with  the 
subject.  One  might  suppose  that  it  would  be  equally 
permissible  to  take  a  proposition  in  which  the  predi- 
cate is  affirmed  of  the  subject  and  obvert  it  by  denying 
*  J.  Parton,  Smoking  and  Drinking,  p.  34. 


THE  NATURE  OF  PROPOSITIONS  61 

this  same  predicate  of  the  negative  of  the  subject, 
but  this  is  not  the  case.  A  concrete  instance  in  which 
such  an  obversion  is  involved  is  furnished  in  the  fol- 
lowing inference: 

' '  The  agreement  of  the  representatives  of  the  great 
European  powers  in  session  at  the  Hague  (June, 
1899),  in  favor  of  a  reduction  of  standing  armies 
would  produce  a  lasting  benefit  to  civilization,  if  it 
could  be  determined  on;  but  as  there  is  little  likeli- 
hood of  such  agreement,  we  may  infer  that  no  benefit 
to  civilization  will  ensue. ' '  * 

In  this  argument  it  is  asserted  (1)  that  a  Confer- 
ence which  resulted  in  the  agreement  of  the  powers 
to  reduce  standing  armies  would  be  a  benefit,  and 
(2)  that  this  Conference  will  not  result  in  such  an 
agreement.  From  these  two  propositions  it  is  inferred 
that  no  benefit  will  result.  It  is  plain,  however, 
that  this  conclusion  is  not  warranted.  The  Confer- 
ence may  be  a  benefit  for  other  reasons.  In  order  to 
justify  the  conclusion,  we  must  take  the  first  state- 
ment as  equivalent  to,  '  A  Conference  that  does  not 
result  in  the  agreement  of  the  powers  to  reduce 
standing  armies  will  not  be  a  benefit.'  That  is  to 
say,  the  obversion  is  accomplished  by  denying  the 
predicate  of  the  negative  of  the  subject.  The  two 
propositions,  however,  are  not  equivalent  to  each 
other  and  the  inference,  therefore,  involves  a  false 
obversion. 

Correct  obversion,  it  will  be  seen,  requires  that  our 
manipulations  be  confined  to  the  predicate  of  the 
proposition  which  is  to  be  obverted.     An  obversion 

*  Newspaper  clipping,  quoted  by  Lafleur,  Illustrations  of 
Logic,  No.  174. 


62  AN  OUTLINE  OF  LOGIC 

which  involves  the  negative  of  the  subject  is  a  false 
obversion.  We  may  take  as  our  next  illustration  of 
false  obversion  a  proposition  which  in  its  original 
form  is  negative.  This  proposition  is  taken  as  equiv- 
alent to  a  proposition  in  which  the  predicate  is  af- 
firmed of  the  negative  of  the  subject.  The  fallacy 
occurs  in  the  following  argument: 

"  No  trifling  business  will  enrich  those  engaged  in 
it ;  a  mining  speculation  is  no  trifling  business ;  there- 
fore a  mining  speculation  will  enrich  those  engaged 
in  it."  (Whately.) 

While  this  reasoning  is  not  likely  to  mislead,  be- 
cause our  knowledge  of  the  facts  warns  us  against 
the  conclusion,  we  may  be  a  little  puzzled  to  account 
for  the  seeming  coherence  of  the  argument.  Analysis 
shows  that  this  apparent  coherence  is  due  to  a  false 
obversion,  '  No  trifling  business  will  enrich  those  en- 
gaged in  it  '  being  taken  as  equivalent  to,  '  A  business 
that  is  not  trifling  will  enrich  those  engaged  in  it.' 
If  we  grant  the  truth  of  this  false  obverse,  then  it 
is  true  that  a  mining  speculation,  which  is  a  business 
that  is  not  trifling,  will  enrich  those  engaged  in  it. 
The  obversion,  however,  is  false,  for  it  assumes  that 
a  statement  about '  trifling  business  '  warrants  a  state- 
ment about  something  entirely  different,  viz.,  about 
a  '  business  that  is  not  trifling. ' 

False  Conversion. —  It  was  pointed  out  that  in  con- 
version terms  which  are  undistributed  in  the  original 
proposition  must  remain  undistributed  in  the  proposi- 
tion derived  by  conversion.  If  the  second  proposition 
distributes  a  term  which  in  the  first  is  not  distributed, 
the  scope  of  that  term  is  extended,  which  is  obviously 
not   permissible.     False   conversion  has  to   do   with 


THE  NATURE  OF  PROPOSITIONS  63 

errors  in  distribution.    The  following  argument  is  a 
case  in  point: 

"  When  we  say  that '  the  murderer  deserves  death,' 
are  we  quite  sure  that  we  are  right  as  to  the  fact? 
Perhaps  he  may  be  insane;  does  he  deserve  death  then  ? 
...  To  kill  oneself  is  no  better  than  to  kill  a  fellow- 
creature;  and  if  temporary  insanity  be  the  proper 
verdict  in  the  one  case,  why  should  it  not  also  be 
proper  in  the  other?  Both  crimes  indicate  insensi- 
bility to  consequences;  and  what  is  insensibility  to 
consequences  but  insanity  itself?  To  us  the  deed  of 
murder  seems  so  intensely  unnatural,  so  horrible,  so 
awful,  that  we  can  only  suppose  it  to  be  the  frenzied 
conception  of  a  mind  violently  wrenched  from  its 
propriety  and  responsible  to  no  moral  tribunal  but 
the  Eternal  one."* 

In  this  argument  it  is  asserted  that  '  Insensibility 
to  consequences  is  insanity,'  and  that  the  murderer 
is,  therefore,  to  be  considered  insane.  The  only  reason, 
however,  that  is  offered  for  this  opinion  is  that  the 
crime  is  '  so  intensely  unnatural.'  This  is  hardly 
conclusive  evidence.  It  seems  likely  that  to  the  writer 
the  assertion  appeared  plausible,  because  '  Insensibility 
to  consequences  is  insanity  '  is  not  clearly  distin- 
guished from  '  Insanity  is  insensibility  to  conse- 
quences. '  The  latter  of  these  propositions  is  presuma- 
bly true,  but  does  not  suffice  to  give  the  conclusion; 
the  former  does  suffice  for  the  conclusion,  but  its  truth 
is  not  above  suspicion.  The  two  propositions  are  easily 
taken  as  identical,  because  we  tend  to  pass  from 
'  Insanity  is  insensibility  to  consequences  '  to  '  In- 
sensibility to  consequences  is  insanity,'  by  simple  con 
*  Eclectic  Review,  July,   1849,  p.   117. 


64  AN  OUTLINE  OF  LOGIC 

version.  The  proposition  thus  converted,  however,  is 
proposition  A  and  must  be  converted  by  limitation. 
The  true  converse,  therefore,  is,  '  Some  insensibility 
to  consequences  is  insanity. '  Granted  that  this  propo- 
sition is  true,  it  still  remains  to  be  determined  whether 
the  insensibility  to  consequences  displayed  by  the 
murderer  is  of  the  kind  that  is  identical  with  insanity. 
The  illustration  just  cited  shows,  if  the  interpreta- 
tion is  correct,  how  easy  it  is  to  confuse  a  meaning 
which  is  true,  or  at  least  plausible,  but  which  does 
not  give  the  desired  conclusion,  with  another  meaning 
which  does  indeed  warrant  the  conclusion,  but  which 
is  not  true,  or  at  least  not  beyond  serious  doubt.  The 
fallacy  is  not  likely  to  occur,  as  a  rule,  except  when 
the  subject  term  and  the  predicate  term  of  the  propo- 
sition are  very  nearly  co-extensive.  "  Thus  no  one 
would  think  of  converting  the  proposition, '  All  United 
States  Senators  are  members  of  Congress,'  into,  '  All 
members  of  Congress  are  United  States  Senators,' 
but  many  might  fall  into  the  fallacy  of  converting 
the  proposition,  '  All  the  Democrats  in  the  Senate 
voted  against  the  bill,'  into,  '  All  Senators  who  voted 
against  the  bill  were  Democrats. '  "  * 
*  Hibben,  Logic,  p.  113. 


CHAPTER  VI 

THE  CATEGORICAL  SYLLOGISM 

The  Purpose  of  the  Syllogism. — We  have  found 
that  classification  is  important  for  reasoning,  because 
certain  qualities  or  attributes  go  together  or  tend  to 
go  together.  If  we  have  classified  correctly,  we  are 
enabled  to  anticipate  experience  and  say  in  advance, 
'  All  A  is  B.'  We  know  that  all  fire  burns,  without 
first  testing  every  possible  case  of  fire,  past,  present, 
and  future.  Such  classification  is,  indeed,  frequently 
surrounded  by  danger,  as  the  facts  of  ambiguity  at- 
test. By  what  methods  we  verify  the  correctness  of 
our  classifications  is  a  problem  of  extreme  importance, 
but  one  that  must  be  postponed  in  favor  of  another 
problem  of  smaller  magnitude.  The  latter  is  the 
special  problem  of  the  syllogism,  and  it  raises  this 
question:  Assuming  that  certain  propositions  are  true, 
i.e.,  that  they  are  accepted  without  dispute,  how  can 
they  be  made  to  support  some  new  proposition? 
This  question  presupposes  that  certain  classifications 
are  already  at  hand,  and  assumes  that  they  are  trust- 
worthy. It  thus  leaves  aside  the  whole  subject  of 
ambiguity,  and  it  does  not  concern  itself  to  ascertain 
how  our  original  propositions  are  secured.  Its  special 
function  is  to  determine  how  given  propositions  must 
be  related  to  each  other,  in  order  to  demonstrate  the 
truth  of  some  new  proposition. 

65 


66  AN  OUTLINE  OF  LOGIC 

It  should  be  noted  at  the  outset  that  the  syllogism 
does  not  attempt  to  tell  us  how  reasoning  actually 
goes  on,  but  how  the  conclusion  that  is  drawn  may 
be  justified  or  necessitated.  It  deals  with  the  prin- 
ciples that  underlie  the  process  of  reasoning,  and  not 
directly  with  the  reasoning  process  itself. 

The  Definition  of  the  Syllogism. — The  stock  ex- 
ample of  a  syllogistic  argument  is  the  following: 

All  men  are  mortal; 
Socrates  is  a  man; 
Therefore  Socrates  is  mortal. 

This  argument,  when  inspected,  is  found  to  consist 
of  three  propositions,  the  last  one  being  the  conclusion, 
while  the  other  two  are  called  the  premises.  The 
premises  are  merely  unsupported  assertions  and  may 
at  times  be  wrong.  The  conclusion,  on  the  other 
hand,  does  not  stand  alone,  but  sustains  to  the  premises 
a  peculiar  relation  called  validity.  To  say  that  a 
conclusion  is  valid  is  not  to  say  that  it  is  true,  but 
that  it  must  be  true  if  the  premises  are  true.  A 
syllogism,  therefore,  is  sufficiently  defined  if  we  say 
that  it  "  consists  of  three  propositions  so  related  that 
one  of  them  is  involved  or  implied  in  the  other  two."  * 
The  Parts  of  the  Syllogism. — In  order  to  obtain 
a  valid  conclusion,  the  premises  must  be  related  to 
each  other  in  a  certain  way.  We  cannot  obtain  valid 
conclusions  by  combining  any  two  propositions  at 
random.    If  we  had  said : 

All  men  are  mortal; 
Socrates  was  a  Greek; 

*  Minto,  Logic,  p.  167. 


THE  CATEGORICAL  SYLLOGISM  67 

no  conclusion  could  be  drawn,  because  the  proposi- 
tions bear  no  relation  to  each  other.  These  two  propo- 
sitions represent  a  total  of  four  terms,  '  men,' 
'mortal,'  'Socrates,'  and  'Greek.'  The  previous 
argument,  on  the  other  hand,  contains  but  three  terms, 
viz., '  men,' '  mortal,'  and  '  Socrates,'  the  term  '  man  ' 
being  common  to  both  propositions.  In  order,  then, 
to  serve  as  the  premises  for  a  valid  conclusion,  the 
propositions  in  question  must  have  a  common  term. 
This  common  term  constitutes  a  point  of  relation  or 
of  comparison  between  the  two  premises.  We  are 
enabled  to  ascertain  the  relation  of  the  other  two  terms 
to  each  other,  because  each  of  them  bears  a  certain 
relation  to  the  common  term.  The  latter  appears  in 
both  premises,  but  does  not  appear  in  the  conclusion. 
It  is  known  as  the  Middle  Term,  because  it  serves  as 
a  connecting  link  between  the  two  terms  that  appear 
in  the  conclusion.  This  arrangement  shows  why  the 
syllogism  is  sometimes  described  as  a  process  of  com- 
parison. 

If  we  symbolize  the  subject  term  of  the  conclusion 
by  S,  the  predicate  term  of  the  conclusion  by  P,  and 
the  middle  term  by  M,  the  form  of  this  particular 
syllogism  is  as  follows: 

M— P 

S— M 

.  * .  S— P 

As  a  matter  of  terminology  we  may  note  that  P  is 
known  in  syllogistic  logic  as  the  major  term,  and  S 
as  the  minor  term;  while  the  premise  that  contains 
P  is  called  the  major  premise,  and  the  one  that  con- 


68  AN  OUTLINE  OF  LOGIC 

tains  S  is  called  the  minor  premise.  In  the  arrange- 
ment of  the  three  propositions  that  constitute  the 
syllogism,  it  is  customary  to  place  the  major  premise 
first,  then  the  minor  premise,  and  lastly  the  conclu- 
sion. This  is  sometimes  called  the  '  logical  form  '  of 
the  syllogism.  It  will  be  noticed  that  '  logical  form  ' 
is  a  term  applied  to  both  propositions  and  syllogisms. 
The  logical  form  of  the  syllogism  is  not  always,  or 
even  usually,  followed  in  actual  argument,  and  so 
if  we  attempt  to  reduce  an  argument  to  its  logical 
form,  it  is  expedient  to  pick  out  first  the  conclusion, 
because  the  conclusion  gives  us  the  clue  to  the  major 
and  minor  premises.  This  is  exemplified  in  the  follow- 
ing argument:  '  He  must  be  a  stockholder,  for  he 
attended  the  meeting,  and  all  who  attended  the  meet- 
ing were  stockholders.'  Here  the  conclusion,  '  He 
must  be  a  stockholder,'  stands  first.  Having  dis- 
covered the  conclusion,  we  know  that  the  proposition 
which  contains  the  subject, '  He, '  is  the  minor  premise, 
and  that  the  proposition  containing  the  predicate, 
'  stockholder,'  is  the  major  premise.  Properly  ar- 
ranged, therefore,  the  argument  would  read : 

All  who  attended  the  meeting  were  stockholders; 
He  attended  the  meeting; 
Therefore,  he  is  a  stockholder. 

The  Inclusion  and  Exclusion  of  Classes. — If  we 
inquire  into  the  reason  why  the  two  terms  of  the 
conclusion  are  called  major  term  and  minor  term 
respectively,  we  come  upon  the  conception  that  is 
fundamental  to  the  categorical  syllogism.  In  this 
syllogism  propositions  are  regarded  solely  from  the 


THE  CATEGORICAL  SYLLOGISM  69 

standpoint  of  the  inclusion  and  exclusion  of  classes. 
So  regarded,  the  proposition,  '  All  men  are  mortal,' 
asserts  that  the  class  '  men  '  falls  within  the  larger 
class  '  mortals  ';  and  the  proposition,  '  Socrates  is  a 
man,'  asserts  that  '  Socrates  '  is  a  class  which  falls 
within  the  larger  class  '  men.'  We  have,  therefore, 
three  classes,  '  Socrates,'  '  men,'  and  '  mortals,'  and 
these  classes  differ  in  extent  or  scope.  In  the  typical 
form  of  the  syllogism,  P  represents  the  largest  of 
the  classes  involved,  while  S  represents  the  smallest. 
4  Mortals,'  the  predicate  term,  represents  a  larger 
class  than'  men,'  and  is  hence  called  the  major  term; 
while  '  Socrates,'  the  subject  term,  represents  a 
smaller  class  than  '  men  '  and  is  therefore  called  the 
minor  term. 

In  order  to  carry  through  consistently  this  treat- 
ment in  terms  of  classes,  it  is  necessary  to  reduce 
all  propositions  to  logical  form,  so  as  to  bring  out 
clearly  the  relations  of  the  classes.  The  change  in 
verbal  form  that  is  necessary  for  this  purpose  may 
be  quite  extensive.  To  take  a  simple  case,  if  we  say, 
'  Presidents  are  persons  having  great  responsibilities,' 
the  fact  that  '  Presidents  '  constitute  a  part  of  the 
larger  class,  '  persons  having  great  responsibilities, '  is 
much  more  clear  than  if  we  had  said,  '  Presidents 
have  great  responsibilities.'  From  the  standpoint  of 
classes,  '  no  men  are  perfect,'  means  that  the  classes 
'  men  '  and  '  perfect  '  exclude  each  other ; '  Some  men 
are  trustworthy,'  means  that  the  class  '  men  '  and 
the  class  '  trustworthy  beings  '  overlap  in  part,  that 
some  part  at  least  of  the  class  '  men  '  falls  within 
the  class  '  trustworthy  beings  ';  and  '  Some  men  are 
n.Qt  trustworthy  '  means  that  some  part  at  least  of 


70  AN  OUTLINE  OF  LOGIC 

the  class  '  men  '  falls  outside  the  class  '  trustworthy 
beings.' 

One  advantage  of  this  method  of  treatment  is  that 
these  arguments  are  readily  tested  by  a  diagram,  since 
the  relations  of  classes  can  be  easily  represented  in 
spatial  form.  Thus  a  larger  circle  to  represent 
'  mortal,'  including  a  smaller  circle  to  represent 
'  men, '  expresses  pictorially  the  proposition,  '  All  men 


are  mortal  ';  and  a  circle  within  the  second  circle 
symbolizes  the  proposition,  '  Socrates  is  a  man.'  The 
conclusion,  '  Socrates  is  mortal,'  signifies  that  if 
Socrates  is  included  within  the  circle  of  '  men,'  he 
is  necessarily  included  within  the  larger,  circle  of 
'  mortals.' 

The  Rules  of  the  Syllogism. — By  resort  to  dia- 
grams, whenever  necessary,  we  can  determine  in  any 
specific  instance  whether  a  given  pair  of  propositions 
will  serve  as  the  premises  for  a  valid  conclusion. 
Usually,  however,  a  set  of  rules  are  offered  to  which 
the  syllogism  must  conform.  These  rules  merely  for- 
mulate what  the  diagrams  or  circles  may  be  made  to 
demonstrate.     They  are  as  follows: 

(1)  In  every  syllogism  there  should  be  three  and 
not  more  than  three  terms,  and  these  terms  must  be 
used  throughout  in  the  same  sense. 


THE  CATEGORICAL  SYLLOGISM  71 

(2)  The  middle  term  must  be  distributed  at  least 
once  in  the  premises. 

(3)  No  term  must  be  distributed  in  the  conclusion 
that  was  not  distributed  in  one  of  the  premises. 

(4)  No  conclusion  may  be  drawn  from  two  negative 
premises. 

(5)  If  one  premise  is  negative,  the  conclusion  must 
be  negative. 

(6)  No  conclusion  may  be  drawn  from  two  par- 
ticular premises. 

(7)  If  one  of  the  premises  is  particular,  the  con- 
clusion must  be  particular. 

The  reason  for  the  first  of  these  rules  has  already 
appeared.  Unless  there  are  three  and  only  three  terms, 
we  have  no  standard  for  comparison,  i.e.,  no  common 
point  of  reference,  by  which  we  can  determine  the 
relation  of  the  two  terms  in  the  conclusion  to  each 
other.  Inference  is  consequently  impossible.  Certain 
qualifications  of  this  rule  will  be  discussed  a  little  later 
in  this  chapter  under  the  heading,  '  Sorites.' 

The  second  rule,  that  the  middle  term  must  be  dis- 
tributed at  least  once,  is  based  upon  the  fact  that 
the  middle  term  is  the  medium  of  comparison  for 
the  other  two  terms.  If  neither  premise  makes  an 
assertion  about  the  whole  class  designated  by  the 
middle  term,  it  may  happen  that  one  premise  applies 
to  one  part  of  that  class,  while  the  other  premise 
applies  to  some  other  part.  This  is  illustrated  in 
the  following  syllogism : 

All  good  citizens  are  interested  in  politics; 
These  men  are  interested  in  politics; 
Therefore  these  men  are  good  citizens. 


72  AN  OUTLINE  OF  LOGIC 

It  may  be,  of  course,  that  these  men  are  interested  in 
politics  for  purely  selfish  reasons.  That  the  conclu- 
sion does  not  necessarily  follow  appears  from  the 
accompanying  diagram.    '  These  men  '  may  fall  either 


inside  or  outside  the  class,  '  good  citizens.'  If  we 
were  to  perform  a  false  conversion  of  the  major 
premise  and  say,  '  All  who  are  interested  in  politics 
are  good  citizens,'  the  conclusion  would  be  valid,  but 
the  truth  of  this  new  major  premise  would  be  more 
than  questionable.  A  violation  of  this  second  rule  is 
known  as  an  Undistributed  Middle  Term,  or  more 
briefly,  as  an  Undistributed  Middle. 

The  third  rule,  which  forbids  us  to  distribute  in 
the  conclusion  a  term  that  was  not  distributed  in  the 
premises,  implies  the  obvious  truth  that  if  the  asser- 
tion made  in  the  premises  is  meant  to  apply  to  some 
part  of  a  class  only,  it  must  not  be  construed  in  the 
conclusion  as  though  it  applied  to  the  class  as  a 
whole.  It  means  that  a  term  must  not  be  used  more 
widely  in  the  conclusion  than  it  was  used  in  the 
premises.  This  rule  may  be  violated  in  connection 
with  either  the  major  or  the  minor  term,  and  the  fal- 
lacies which  result  are  known  in  logic  parlance  as  the 
Illicit  Process  of  the  major  and  minor  terms,  respect- 
ively, or,  more  briefly,  as  illicit  major  or  illicit  minor, 


- 

THE  CATEGORICAL  SYLLOGISM  73 

An  example  of  an  illicit  major  is  given  in  the 
syllogism  below: 

All  the  democrats  voted  against  this  measure; 

This  man  is  not  a  Democrat; 

Therefore  this  man  did  not  vote  against  this  measure. 

The  conclusion  makes  an  assertion  regarding  the  whole 
class  of  '  Those  who  voted  against  this  measure,'  viz., 
that  the  class  excludes  '  this  man.'  But,  as  is  shown 
in  the  diagram,  the  fact  that '  this  man  '  is  outside  the 


Those  voting 
against 


[Democrats]  *Tnis 


class  '  Democrats  '  does  not  determine  whether  he 
is  inside  or  outside  the  class, '  Those  who  voted  against 
this  measure.'  The  inference  gains  whatever  plausi- 
bility it  may  possess  from  the  tacit  conversion  of 
the  major  premise  to,  '  All  who  voted  against  this 
measure  are  Democrats.'  A  diagram  will  show  that 
if  the  major  is  thus  converted,  the  conclusion  is 
valid. 

The  next  argument  illustrates  the  fallacy  of  illicit 
minor : 

All  good  citizens  pay  their  taxes; 
All  good  citizens  vote  at  elections; 
Therefore  all  who  vote  at  elections  pay  their  taxes. 


74 


AN  OUTLINE  OF  LOGIC 


This  inference,  as  the  accompanying  diagram  shows,  is 
unwarranted.    If  the  premises  are  true,  the  two  classes 


must  indeed  overlap,  and  so  it  must  be  true  that  some 
who  vote  at  elections  are  good  citizens.  But  since 
the  premises  say  nothing  about  the  whole  class  of 
'  those  who  vote  at  elections,'  we  are  not  permitted  to 
do  so  in  the  conclusion.  The  conclusion  is  valid  only 
if  we  convert  the  minor  premise  to  '  All  who  vote  at 
elections  are  good  citizens.' 

That  no  conclusion  can  be  drawn  from  negative 
premises,  as  is  stated  in  the  fourth  rule,  is  evident 
if  we  note  that  the  premises  inform  us  merely  that 
S  and  P  both  fall  outside  of  M  and  thus  give  us  no 
sort  of  clue  as  to  the  relation  which  they  may  sustain 
to  each  other.  This  appears  from  the  following  argu- 
ment: 

No  pauper  has  a  vote; 
John  is  no  pauper; 
Therefore  John  has  a  vote. 

If  we  represent  this  syllogism  by  circles,  we  see  that 
while  '  John  '  is  outside  the  class  of  paupers,  he  is  not 
necessarily  included  in  the  class  of  '  those  who  have  a 
vote. '    The  appearance  of  validity  seems  to  be  due  to 


THE  CATEGORICAL  SYLLOGISM  75 

the  fact  that  '  no  pauper  has  a  vote  '  bears  a  certain 
resemblance  to  the  proposition,  '  Those  who  are  not 


paupers  have  a  vote,'  i.e.,  there  is  a  certain  tempta- 
tion to  perform  a  false  obversion. 

The  rule  that  two  negative  premises  cannot  yield 
a  valid  conclusion  is  apt  to  mislead  occasionally,  unless 
we  distinguish  between  propositions  which  are  nega- 
tive in  form  only  and  those  which  are  negative  in 
meaning.  The  following  is  an  example  of  a  syllogism 
that  appears  to  have  two  negative  premises  but  never- 
theless permits  us  to  draw  a  valid  conclusion: 

Nobody  who  is  not  thirsty  is  suffering  from  fever, 

This  person  is  not  thirsty, 

Therefore  this  person  is  not  suffering  from  fever  (Minto). 

This  is  a  valid  conclusion,  for  the  reason  that  the 
inference  is  based  not  upon  any  assigned  quality,  but 
upon  the  absence  of  a  quality,  viz.,  '  thirsty.'  The 
major  is  equivalent  to  '  Wherever  thirst  is  absent 
fever  is  absent.'  Such  a  syllogism  can  be  made  cor- 
rect in  form  by  making  the  minor  premise  read,  '  This 
person  is  one  who  is  not  thirsty.'  The  '  not  '  is  thus 
made  to  belong  to  the  predicate  and  not  to  the  copula. 


76  AN  OUTLINE  OF  LOGIC 

The  remaining  rules  may  be  dismissed  more  briefly. 
Rule  five,  which  states  that  if  one  premise  is  negative 
the  conclusion  must  be  negative,  is  necessarily  true, 
because  under  such  conditions  one  of  the  other  two 
terms  agrees,  while  the  other  does  not  agree,  with  the 
middle  term.  Hence  the  two  do  not  agree  with  each 
other,  i.e.,  the  conclusion  must  be  negative.  The  sixth 
and  seventh  rules  are  based  upon  the  fact  that  [as 
stated  in  rules  (2)  and  (3)],  the  middle  term  must 
be  distributed  at  least  once,  and  that  no  term  must 
be  distributed  in  the  conclusion  if  it  was  not  dis- 
tributed in  the  premises.  It  will  be  found  that  if 
both  premises  are  particular  one  or  the  other  of  these 
two  rules  is  violated,  and  that  the  same  is  true  if 
we  attempt  to  draw  a  universal  conclusion  when  one 
of  the  premises  is  particular.     (3  /    //? 

The  Figures  of  the  Syllogism. —  By  '  figure  '  is 
meant  the  form  or  arrangement  of  the  syllogism  as 
determined  by  the  position  of  the  middle  term.  Since 
the  middle  term  may  function  in  the  premises  as 
either  the  subject  or  the  predicate,  four  arrangements 
or  forms  are  possible.  These  arrangements  are  ex- 
emplified in  the  following  syllogisms : 

FIGURE  I 

All  men  are  mortal;  M — P 

Socrates  is  a  man;  S — M 

Therefore   Socrates  is  mortal.  . " .  S — P 

FIGURE  II 

All  men  are  mortal;  P — M 

Inanimate  beings  are  not  mortal;  S — M 

Therefore  inanimate  beings  are  not  men.         . ' .  S — P 


THE  CATEGORICAL  SYLLOGISM  77 

FIGURE  III 

All  men  are  mortal;  M — P 

All  men  are  fallible;  M — S 

Therefore  some  fallible  beings  are  mortal.    .  * .  S — P 

FIGURE  IV 

All  men  are  mortal;  P — M 

All  mortals  are  fallible;  M — S 

Therefore  some  fallible  beings  are  men.        . ' .  S — P 

In  the  first  figure  the  middle  term  is  the  subject 
of  the  major  premise  and  the  predicate  of  the  minor 
premise.  In  the  second  figure  it  is  the  predicate  of 
both  premises.  In  the  third  figure  it  is  the  subject 
of  both  premises.  In  the  fourth  figure  it  is  the  predi- 
cate of  the  major  premise  and  the  subject  of  the  minor 
premise.  It  may  be  remarked  that  while  the  fourth 
figure  is  theoretically  possible,  it  is  of  no  particular 
practical  importance  and  is  not  recognized  in  Aris- 
totle's doctrine  of  the  syllogism. 

Reduction. — The  first  figure  was  regarded  by  Aris- 
totle as  the  most  direct  and  convincing,  and  was 
called  by  him  the  perfect  figure.  In  the  first  figure 
the  major  premise  is  a  universal  proposition,  and  the 
minor  points  out  something  which  this  universal  in- 
cludes. The  other  figures  were  called  the  imperfect 
figures,  and  the  process  of  changing  these  to  the  first 
figure  is  called  reduction.  Elaborate  rules  governing 
the  process  of  reduction  were  formulated  during  the 
Middle  Ages.  Reduction  is  accomplished  through  cer- 
tain processes  of  obversion  and  conversion,  and 
through  the  transposition  of  the  premises  whenever 
necessary.     The  syllogism,  for  example,  in  the  third 


78  AN  OUTLINE  OF  LOGIC 

figure  above,  may  be  reduced  to  the  first  figure  by 
simply  converting  the  minor  premise  so  as  to  makj 
it  read,  '  Some  fallible  beings  are  men  ';  and  the 
syllogism  in  the  fourth  figure  may  be  reduced  by  trans- 
posing the  premises  and  converting  the  conclusion. 
Reduction  is  of  interest  chiefly  because  it  shows  that 
whenever  we  put  an  argument  in  the  form  of  a  syl- 
logism, the  particular  form  of  syllogism  that  we  adopt 
is  more  or  less  a  matter  of  accident. 

Sorites,  or  Chain  of  Reasoning. — A  Sorites  is  a 
chain  of  reasoning  in  which  the  two  terms  of  the 
conclusion  are  united  through  the  mediation  of  more 
than  one  intervening  or  connecting  term.  It  may 
assume  either  of  the  two  following  forms : 


A  is  B; 

All  negroes  are  men; 

B  is  C; 

All  men  are  vertebrates; 

C  is  D; 

All  vertebrates  are  animals; 

D  is  E; 

All  animals  are  mortal; 

A  is  E.      , 

. ' .  All  negroes  are  mortal. 

II 

D  is  E; 

All  animals  are  mortal; 

C  is  D; 

All  vertebrates  are  animals; 

B  is  C; 

All  men  are  vertebrates; 

A  is  B; 

All  negroes  are  men; 

A  is  E. 

. ' .  All  negroes  are  mortal. 

It  is  possible  to  treat  a  Sorites  as  an  abbreviated 
form  of  syllogistic  inference,  because  the  chain  of 
reasoning  may  be  resolved  into  a  series  of  syllogisms, 
each  of  which,  except  the  last,  yields  a  conclusion 


THE  CATEGORICAL  SYLLOGISM  79 

that  serves  as  a  premise  in  the  succeeding  syllogism. 
From  this  point  of  view,  the  first  of  the  above  in- 
ferences is  equivalent  to  three  complete  syllogisms, 
as  follows: 

I  II  III 


B  is  C; 

C  is  D; 

D  is  E; 

A  is  B; 

A  is  C; 

A  is  D; 

A  is  C. 

. ' .  A  is  D. 

.  \  A  is  E. 

Inferences  in  Quantitative  Relations. — Certain  in- 
ferences that  deal  with  quantitative  relations  give 
valid  conclusions,  in  spite  of  the  fact  that  they  seem 
to  violate  the  rules  of  the  syllogism.  The  following 
are  examples: 


A  is  greater  than  B; 

B  is  greater  than  Cj 

.*,  A  is  greater  than  C. 

II 

A  is  north  of  B; 

B  is  north  of  C; 

. " .  A  is  north  of  C. 

In  form  these  arguments  are  exactly  the  same  as: 

A  is  the  landlord  of  B; 

B  is  the  landlord  of  C; 

.  * .  A  is  the  landlord  of  C. 

Yet  this  latter  conclusion  does  not  follow  from  the 
premises.    All  of  these  syllogisms,  it  will  be  noticed, 


80  AN  OUTLINE  OF  LOGIC 

have  four  terms.  What  requires  explanation,  there- 
fore, is  the  fact  that,  in  spite  of  this  apparent  ir- 
regularity, it  is  possible  to  draw  valid  conclusions 
when  the  subject-matter  concerns  relations  of  quantity. 
The  explanation  of  this  fact  is,  in  brief,  that  the 
valid  conclusions  are  possible  because  they  rest  upon 
a  true  major  premise  which  does  not  appear  in  the 
argument.  If  A  is  north  of  B,  and  B  is  north  of  C, 
we  can  infer  the  relation  of  A  and  C,  because  we 
are  familiar  with  the  nature  of  space  relations.  To 
state  the  law  or  the  generalization  which  underlies 
the  inference  is  a  matter  of  some  difficulty.  Accord- 
ing to  some  writers  the  inference,  in  correct  syllogistic 
form,  would  read  about  like  this: 

Whatever  is  north  of  that  which  is  north  of  another 

is  north  of  that  other; 
A  is  something  that  is  north  of  that  which  is  north  of  C; 
.  * .  A  is  north  of  C. 

It  is  true  that  we  never  formulate  the  major  premise 
of  this  inference,  and  that  we  usually  do  not  even 
suspect  its  presence.  But,  as  we  shall  see  a  little 
later  (see  Chapter  VIII),  the  suppression  of  one  of 
our  premises  is  a  frequent  occurrence  in  everyday 
reasoning.  This  major  premise  is  not  formulated,  just 
because  the  relationship  which  it  expresses  is  so  simple 
and  obvious.  This  relationship  is  peculiar  to  the 
realm  of  quantity,  and  so  the  recognition  of  this 
relationship  enables  us  to  make  inferences  in  this 
realm  which  have  no  precise  parallel  in  other  fields. 


CHAPTER  VII 

HYPOTHETICAL  AND  DISJUNCTIVE 
SYLLOGISMS 

In  a  previous  chapter  propositions  were  distin- 
guished as  categorical  and  conditional.  The  latter 
kind  again  presents  two  forms,  the  hypothetical  and 
the  disjunctive.  Corresponding  to  the  two  kinds  of 
conditional  propositions,  we  have  two  kinds  of  con- 
ditional syllogisms,  the  hypothetical  and  the  dis- 
junctive syllogism,  just  as  the  syllogism  discussed  in 
the  preceding  chapter  corresponds  to  the  categorical 
proposition. 

The  Hypothetical  Syllogism. — It  was  pointed  out 
that  the  hypothetical  proposition  expresses  a  condition 
and  a  result,  e.g.,  '  If  it  storms,  the  boat  will  capsize.' 
The  part  that  expresses  the  condition,  '  if  it  storms,'  is 
called  the  antecedent ;  the  part  that  expresses  the  result, 
'  the  boat  will  capsize, '  is  called  the  consequent.  The 
reason  for  this  distinction  will  appear  in  a  moment. 

In  hypothetical  syllogisms  both  hypothetical  and 
categorical  propositions  are  employed.  The  hypo- 
thetical syllogism  consists  of  a  hypothetical  major 
premise  and  a  categorical  minor  premise.  The  follow- 
ing is  an  example: 

If  the  strike  has  been  called  off,  the  men  are  back  at  work; 
The  strike  has  been  called  off; 
Therefore  the  men  are  back  at  work. 

81 


82  AN  OUTLINE  OF  LOGIC 

In  this  case  the  minor  affirms  the  antecedent.  A 
valid  conclusion  may  also  be  drawn  if  the  minor  denies 
the  consequent,  as  in: 

If  the  strike  has  been  called  off,  the  men  are  back  at  work; 

The  men  are  not  back  at  work; 

Therefore  the  strike  has  not  been  called  off. 

These  two  illustrations  represent  the  gist  of  the 
hypothetical  sjdlogism.  The  rule  that  governs  this 
syllogism  is :  The  minor  premise  must  either  affirm  the 
antecedent  or  deny  the  consequent.  If  the  antecedent 
exists,  the  consequent  must  also  exist.  Conversely,  if 
the  consequent  does  not  exist,  it  follows  that  the  ante- 
cedent, which  it  invariably  accompanies,  does  not  exist 
either. 

Error  arises  if  we  attempt  to  draw  conclusions  from 
a  syllogism  in  which  the  minor  premise  denies  the 
antecedent  or  affirms  the  consequent.  Thus  with  the 
same  major  premise  as  above,  and  with  the  minor, 
1  The  strike  has  not  been  called  off,'  we  cannot  infer 
that  the  men  are  not  back  at  work,  for  they  may  have 
returned  to  work  without  the  formality  of  calling  off 
the  strike.  If  we  ignore  this  possibility,  we  commit 
the  fallacy  of  denying  the  antecedent.  Nor  can  we 
draw  a  valid  inference  with,  '  The  men  are  back  at 
work,'  as  a  minor.  If  we  conclude  from  this  that 
'  the  strike  has  been  called  off,'  we  again  over- 
look the  possibility  which  has  just  been  mentioned. 
This  fallacy  is  the  fallacy  of  affirming  the  con- 
sequent. 

It  should  be  noticed  that  the  antecedent  may  be 
affirmed  by  a  minor  premise  which  is  negative  in  form 


SYLLOGISMS  83 

and  that  the  consequent  may  be  denied  by  a  minor 
which  is  affirmative  in  form.    For  example: 

If  war  is  not  declared  commerce  will  increase; 
But  war  will  not  be  declared; 
Therefore  commerce  will  increase. 

This  minor  is  affirmative  in  force,  because  the  absence 
of  a  condition,  '  war,'  asserted  by  it  is  a  basis  for  an 
inference.  Or  we  may  say  that  the  absence  of  war 
is  a  state  that  conditions  the  increase  of  commerce. 
Similarly,  in  the  argument: 

If  he  is  the  right  kind  of  man  he  will  not  use  money  to 
secure  his  election; 

But  he  will  use  money  to  secure  his  election; 
Therefore  he  is  not  the  right  kind  of  man. 

the  affirmation  that  he  used  money  is  equivalent  to 
a  denial  that  he  did  not  use  money,  and  hence  it  denies 
the  consequent. 

It  is  evident,  if  we  reflect  a  moment,  that  the  fallacy 
of  denying  the  antecedent  is  in  principle  the  same 
as  that  of  affirming  the  consequent.  In  both  cases 
we  disregard  the  fact  that  the  antecedent  is  not  nec- 
essarily the  only  antecedent  upon  which  the  conse- 
quent depends.  While  it  may  be  true,  therefore,  that 
if  A  is  B  then  C  is  D,  it  need  not  be  true  that  if 
A  is  not  B  then  C  is  not  D ;  nor  need  it  be  true  that 
if  C  is  D  then  A  is  B.  If  every  consequent  had  but 
one  antecedent,  it  would  not  be  fallacious  to  draw  a 
conclusion  by  denying  the  antecedent  or  affirming  the 
consequent. 

If  we  analyze  the  matter  a  little  further,  we  find 


84  AN  OUTLINE  OF  LOGIC 

that  these  fallacies  are  both  due  to  false  obversion. 
This  can  be  best  shown  by  an  illustration.  Suppose 
we  take  for  major  premise  the  proposition,  '  If  he  is 
ambitious,  he  will  work.'  With  either  '  He  is  not 
ambitious  '  or  '  He  will  work  '  as  a  minor,  we  can- 
not draw  a  conclusion.  He  may  decide  to  work, 
because  this  is  a  less  unpleasant  alternative  than 
starvation.  Nor  can  we  draw  a  conclusion  by  sub- 
stituting for  the  original  major  premise  its  true  ob- 
verse, which  is,  '  If  he  is  ambitious,  he  is  not  a  person 
who  will  not  work.'  But  in  case  we  take  the  obverse 
to  be,  '  If  he  is  not  ambitious,  he  will  not  work,'  we 
can  draw  a  valid  conclusion  with  either  of  the  above 
premises  as  a  minor.  The  conclusion  is  then  valid 
because,  through  a  false  obversion,  the  original  major 
premise  is  interpreted  as  equivalent  to  something  that 
is  entirely  different.  In  this  false  obversion,  ambi- 
tion is  assumed  to  be  the  only  condition  upon 
which  the  consequent,  '  willingness  to  work,'  is 
dependent. 

The  Disjunctive  Syllogism. —  A  disjunctive  syl- 
logism is  characterized  by  the  fact  that  its  major 
premise  is  a  disjunctive  proposition,  while  its  minor 
is  categorical.  The  function  of  the  major  premise  is 
to  state  the  different  alternatives  of  which  one  or  the 
other  must  be  true.  The  minor  then  either  specifies 
which  of  the  alternatives  is  true,  or  it  specifies  which 
of  the  alternatives  are  not  true.  In  symbolic  form 
the  disjunctive  syllogism  may  be  expressed  as  follows: 

A  is  either  B  or  C;       Either  A  is  B  or  C  is  D; 
A  is  B;  A  is  B; 

.  * .  A  is  not  C.  . ' .  C  is  not  D. 


SYLLOGISMS  85 

He  acquired  his  money  either  honestly  or  by  fraud ; 

He  acquired  it  honestly; 

Therefore  he  did  not  acquire  it  by  fraud. 

It  is  assumed  that  the  alternatives  mentioned  in  the 
major  premise  are  exclusive  of  each  other.  Unless 
this  is  the  case,  we  cannot  infer  that  because  A  is 
B  it  is  not  C,  although  we  can  be  sure  that  if  A  is 
not  B  it  is  necessarily  C.  '  He  is  either  a  knave 
or  a  fool,'  is  an  example.  If  he  is  not  a  knave,  he 
must  be  a  fool,  but  if  we  should  find  that  he  is  a 
knave,  we  should  have  to  allow  for  the  possibility 
that  he  is  a  fool  as  well.  This  possibility  invalidates 
the  following  inference : 

He  is  either  elected  or  the  ballotbox  was  stuffed; 

He  is  elected; 

Therefore  the  ballotbox  was  not  stuffed. 

It  is  evident  that  the  alternatives  here  mentioned  do 
not  exclude  each  other.  The  candidate  might  be  fairly 
elected,  in  the  sense  that  he  received  a  majority  of  the 
votes  which  were  cast,  but  there  might  be  fraud  at 
the  same  time.  If,  however,  the  minor  premise  denied 
one  of  the  alternatives,  the  conclusion  would  be  valid. 
The  Dilemma. —  In  practical  life  a  dilemma  means 
any  situation  that  offers  two  or  more  alternatives  of 
action,  all  of  which,  however,  are  disagreeable.  In 
logic  a  dilemma  is  an  argument  whose  premises  are 
made  up  of  hypothetical  and  disjunctive  propositions. 
Its  major  consists  of  two  or  more  hypothetical  proposi- 
tions, while  the  minor  is  a  disjunctive  proposition. 
The  following  is  an  example: 


86  AN  OUTLINE  OF  LOGIC 

If  A  is  B,  C  is  D;  and  if  E  is  F,  C  is  D; 
But  either  A  is  B,  or  E  is  F; 
Therefore  C  is  D. 

The  dilemmatie  argument  may  at  times  be  somewhat 
more  complex,  but  the  principle  remains  the  same. 
Thus: 

If  A  is  B,  C  is  D;  and  if  E  is  F,  G  is  H; 
But  either  C  is  not  D  or  G  is  not  H; 
Therefore  either  A  is  not  B,  or  E  is  not  F. 

"  If  this  man  were  wise  he  would  not  speak  ir- 
reverently of  Scripture  in  jest;  and  if  he  were  good, 
he  would  not  do  so  in  earnest.  But  he  does  it  either 
in  jest  or  in  earnest;  therefore  he  is  either  not  wise 
or  not  good."  (Whately.) 

In  the  course  of  the  Lincoln-Douglas  debate  a 
question  was  put  by  Lincoln  to  Douglas,  as  follows: 
"  Can  the  people  of  a  United  States  territory  in  any 
lawful  way,  against  the  wish  of  any  citizens  of  the 
United  States,  exclude  slavery  from  its  limits,  prior 
to  the  formation  of  a  state  constitution?  "  The  ques- 
tion may  be  viewed  as  the  source  of  a  dilemma,  both 
in  the  practical  and  in  the  syllogistic  sense  of  the 
term.  In  fact  it  involved  a  situation  which,  syl- 
logistically,  comprised  more  than  one  dilemma.  They 
may  be  stated  as  follows : 

I.  If  Douglas  answers  yes,  he  offends  the  South,  and  if 
he  answers  no,  he  offends  the  Noi'th; 
But  he  must  answer  either  yes  or  no; 
Therefore  he  will  offend  either  the  South  or  the  North. 


SYLLOGISMS  87 

II.  If  Douglas  offends  the  South,  he  loses  the  nomination 
for  the  Presidency  in  the  next  convention ;  and  if  he  offends 
the  North,  he  loses  the  election  to  the  United  States  Senator- 
ship  (and  his  chances  for  the  Presidency). 

But  he  must  offend  either  the  South  or  the  North; 

Therefore  he  loses  either  the  Presidency  or  the  Senator- 
ship. 

Or,  III.  If  Douglas  offends  the  South,  he  cannot  become 
President;  and  if  he  offends  the  North,  he  cannot  become 
President ; 

But  he  must  offend  either  the  South  or  the  North; 

Therefore  he  cannot  become  President. 


When  rightly  used  the  dilemma  is  an  extremely 
effective  form  of  argument.  Its  effectiveness,  how- 
ever, like  that  of  the  disjunctive  syllogism,  depends 
upon  the  exhaustiveness  with  which  the  alternatives 
are  stated.  In  many,  perhaps  most,  dilemmas  some 
of  the  alternatives  are  overlooked;  so  that  the  argu- 
ment can  be  blocked  by  simply  pointing  out  this  fact. 
"  Thus  if  we  were,  to  argue  that  '  if  a  pupil  is  fond 
of  learning  he  needs  no  stimulus,  and  that  if  he  dis- 
likes learning  no  stimulus  will  be  of  any  avail,  but 
that,  as  he  is  either  fond  of  learning  or  dislikes  it, 
a  stimulus  is  either  useless  or  of  no  avail,'  we  evi- 
dently assume  improperly  the  disjunctive  minor 
premise.  Fondness  and  dislike  are  not  the  only  two 
possible  alternatives,  for  there  may  be  some  who  are 
neither  fond  of  learning  nor  dislike  it,  and  to  these 
a  stimulus  in  the  shape  of  rewards  may  be  desir- 
able."* 

*  Jevons,  Lessons  in  Logic,  p.   168. 


88  AN  OUTLINE  OF  LOGIC 

The  Relation  of  Categorical  and  Conditional 
Syllogisms. —  A  comparison  of  the  categorical  syl- 
logism with  conditional  syllogisms  shows  that  the  two 
differ  widely  in  their  emphasis  or  mode  of  procedure. 
The  categorical  syllogism,  as  traditionally  interpreted, 
concerns  itself  altogether  with  the  relations  of  in- 
clusion and  exclusion  of  classes,  i.e.,  with  the  aspect 
of  denotation  or  extension.  This  works  very  well  as  a 
rule,  although  the  interpretation  in  terms  of  classes 
becomes  rather  artificial  in  some  instances.  For  ex- 
ample, it  is  undeniably  stilted  to  interpret,  '  Pride 
goeth  before  a  fall, '  as  meaning,  '  The  class  of  things 
characterized  by  pride  falls  within  the  class  of  things 
that  go  before  a  fall.'  It  is  stilted  for  the  reason 
that  when  the  statement  is  made,  we  are  not  thinking 
of  the  relations  of  classes  at  all.  Our  attention  is 
occupied  with  the  connotative  or  intensive  side  of  the 
proposition;  or,  to  put  it  differently,  with  the  rela- 
tions of  the  abstract  attributes  or  characters  '  pride  ' 
and  '  fall. '  Extension  and  intension  are  both  genuine 
aspects  of  propositions,  but  they  do  not  necessarily 
receive  the  same  emphasis  in  our  thinking.  Condi- 
tional syllogisms  differ  from  the  categorical  in  that 
they  emphasize  this  intensive  character.  Conditional 
propositions  aim  to  set  forth  universal  principles  or 
abstract  relations  of  conditioning,  with  no  special 
reference  to  the  objects  in  which  those  principles  are 
embodied. 

This  difference,  however,  is  after  all  only  a  differ- 
ence in  emphasis  or  in  point  of  view.  The  form  of 
a  proposition,  therefore,  is  usually  determined  by  what 
happens  to  be  uppermost  in  our  minds.  '  All  men 
are  mortal,'  tends  to  emphasize  the  extensive  side: 


SYLLOGISMS  89 

in  '  Man  is  mortal,'  the  connotative  side  comes  for- 
ward; which  is  perhaps  still  more  apparent  if  we 
say,  '  If  a  being  is  a  man,  he  is  mortal.' 

Since  the  difference  between  categorical  and  condi- 
tional syllogisms  does  not  concern  their  meaning,  it 
is  easy  to  change  a  syllogism  from  one  form  to  another. 
For  the  same  reason  it  is  clear  that  an  argument 
which  is  invalid  in  any  one  of  these  forms  cannot 
be  made  valid  merely  by  being  changed  to  a  different 
form.    The  hypothetical  syllogism — 

If  a  person  is  kind-hearted  he  will  speak  well  of  others ; 

This  person  is  not  kind-hearted; 

Therefore  he  will  not  speak  well  of  others — 

is  invalid,  because  the  minor  premise  denies  the  ante- 
cedent. If  we  change  it  to  the  categorical  form,  we 
have: 

All  persons  who  are  kind-hearted  speak  well  of  others; 

This  person  is  not  kind-hearted; 

Therefore  this  person  does  not  speak  well  of  others. 

In  this  form  the  syllogism  is  invalid,  because  it  com- 
mits the  fallacy  of  illicit  major.  If  in  the  hypo- 
thetical syllogism  we  should  substitute  for  the  minor 
premise  a  premise  that  affirms  the  consequent,  '  This 
person  speaks  well  of  others, '  and  should  then  change 
the  syllogism  to  the  categorical  form,  the  argument 
would  read: 

All  persons  who  are  kind-hearted  speak  well  of  others; 
This  person  speaks  well  of  others; 
Therefore  this  person  is  kind-hearted. 


90  AN  OUTLINE  OF  LOGIC 

In  this  form  the  fallacy  is  still  present,  but  it  now 
appears  as  an  undistributed  middle. 

Disjunctive  propositions  change  their  forms  as  read- 
ily as  hypothetical.  '  A  is  either  B  or  C,'  is  equiv- 
alent to  the  hypothetical  proposition,  '  If  A  is  B  it 
is  not  C,'  or  to  the  categorical  proposition,  '  The  situa- 
tion in  which  A  is  B  is  a  situation  in  which  A  is 
not  C  The  assertion  that  a  Congressman  is  either 
a  Senator  or  a  Representative  means  that  if  a  Con- 
gressman is  a  Senator  he  is  not  a  Representative, 
or  that  no  Congressmen  who  are  Senators  are  Repre- 
sentatives. 

The  Function  of  the  Syllogism. — At  the  begin- 
ning of  our  study  of  the  syllogism  it  was  stated  that 
the  syllogism  makes  certain  assumptions,  i.e.,  it  con- 
fines itself  to  a  certain  part  of  reasoning  and  does 
not  pretend  to  include  the  whole.  In  order  to  see 
clearly  the  function  of  syllogistic  reasoning,  it  is  nec- 
essary to  keep  this  limitation  in  view.  The  categorical 
syllogism,  for  example,  takes  no  heed  of  the  manner 
in  which  classifications  are  made  and  tested,  but  de- 
votes itself  entirely  to  the  relations  of  the  classes  after 
they  have  been  formed.  This  simplifies  the  situation 
immensely,  since  it  puts  aside  one  of  the  most  difficult 
tasks  of  reasoning.  Similarly,  the  hypothetical  syl- 
logism does  not  take  up  its  work  until  the  relations 
of  conditioning  and  conditioned,  with  which  it  oper- 
ates, have  already  been  discovered.  It  assumes  the 
existence  of  this  relation,  just  as  the  categorical  syl- 
logism assumes  the  existence  of  classes;  and  so  it 
likewise  escapes  the  burden  and  the  heat  of  the 
day. 

Essentially  the  same  remarks  apply  to  the  dis- 


SYLLOGISMS  91 

junctive  syllogism.  Given  the  relations  of  disjunction, 
then  the  affirmation  of  one  of  the  alternatives,  as  the 
disjunctive  syllogism  informs  us,  involves  the  denial 
of  the  rest ;  and  conversely,  the  denial  of  all  the  other 
alternatives  is  equivalent  to  the  affirmation  of  the 
one  that  remains.  But  how  the  disjunctive  relations 
are  to  be  discovered  and  tested,  we  are  not  told.  To 
make  sure  that  our  alternatives  are  both  true  and 
exhaustive  in  their  presentation  of  the  situation  is 
ordinarily  the  task  that  requires  the  greatest  effort 
and  involves  the  greatest  risk  of  error;  but  it  is  a 
task  that  falls  outside  the  proper  sphere  of  the  syl- 
logism itself. 

One  of  the  main  functions  of  the  syllogism  comes 
into  view  when  we  examine  the  nature  of  the  fallacies 
that  result  from  the  transgression  of  the  syllogistic 
rules.  The  fallacies  that  may  occur  in  connection  with 
the  categorical  syllogism  group  themselves  under  four 
heads:  (a)  The  fallacy  of  four  terms,  (b)  The  fallacy 
of  undistributed  middle,  (c)  The  fallacies  of  illicit 
major  and  illicit  minor,  (d)  The  fallacy  of  negative 
premises.  The  hypothetical  syllogism  recognizes  only 
the  fallacies  of  denying  the  antecedent  and  affirming 
the  consequent.  With  regard  to  the  disjunctive  syl- 
logism, the  only  fallacy  that  can  well  occur  is  that 
of  imperfect,  or  false,  disjunction.  Of  these  fallacies 
all  but  the  first  and  the  last  can  be  explained  as  due  to 
errors  in  the  quality  or  quantity  of  propositions,  as 
was  pointed  out  in  each  separate  instance  that  arose. 
For  the  two  outstanding  forms  of  fallacy  the  syllogism 
furnishes  no  remedy.  The  form  in  which  the  fallacy  of 
four  terms  is  most  likely  to  impose  upon  us  is  that  of 
ambiguity,  when  the  middle  term  is  identical  in  ap- 


92  AN  OUTLINE  OF  LOGIC 

pearance  but  different  in  meaning  in  the  two  premises. 
This  happens,  for  example,  when  we  argue  that  if 
law  implies  a  lawgiver,  nature  must  have  a  lawgiver, 
since  it  has  laws.  But  the  study  of  the  syllogism 
does  not  aid  us  in  the  detection  of  this  kind  of 
ambiguity.  Nor  does  it  assist  in  the  discovery  of 
imperfect  disjunctions.  But  it  does  give  us  some 
help  in  connection  with  the  special  forms  of  ambiguity 
known  as  obversion  and  conversion.  In  other  words, 
it  forces  us  constantly  to  test  the  meaning  of  our 
propositions  and  thus  tends  to  make  us  sensitive  to 
those  differences  of  meaning  which  are  slurred  over 
in  false  obversion  and  conversion. 

One  function,  then,  of  the  syllogism  is  the  interpre- 
tation of  language,  so  far  as  it  concerns  obversion 
and  conversion.  A  second  function,  the  utility  of 
which  has  not  yet  appeared,  is  to  acquaint  us  with 
the  structure  of  complete  arguments.  The  arguments 
of  everyday  life  are  usually  more  or  less  incomplete. 
We  frequently  take  premises  for  granted,  with  no 
clear  consciousness  that  we  are  doing  so;  with  the 
result  that  we  are  constantly  exposed  to  the  danger 
of  false  assumption.  In  so  far  as  the  syllogism  fosters 
the  habit  of  looking  for  those  parts  of  the  argument 
which  are  suppressed,  it  furnishes  a  protection  against 
this  fallacy.  The  nature  of  false  assumption  and  its 
relation  to  the  syllogism  form  the  topic  of  the  next 
chapter. 


CHAPTER  VIII 

FALSE  ASSUMPTION,  OR  BEGGING  THE 
QUESTION 

Incomplete  Arguments. —  In  our  study  of  the  syl- 
logism we  have  taken  account  only  of  complete  argu- 
ments, because  the  syllogism  aims  only  to  set  forth 
the  structure  embedded  in  inference,  and  not  to  ex- 
amine the  conscious  processes  by  which  the  conclusions 
are  reached.  If  we  compare  the  completed  syllogism 
with  the  more  usual  reasoning  processes,  as  they 
actually  occur  in  our  minds  or  as  they  are  expressed 
in  words,  we  find  that  the  latter  are  much  less  com- 
plete than  the  former.  The  syllogism  has  two  premises 
and  a  conclusion,  all  duly  arranged  and  set  in  order. 
In  our  ordinary  inferences,  on  the  other  hand,  some 
part  of  the  complete  argument  is  apt  to  be  lacking. 
Such  arguments  are  known  in  logic  as  enthymemes, 
because,  as  the  name  implies,  some  part  of  the  argu- 
ment is  not  expressed,  but  is  supposed  to  be  '  in  the 
mind.'    "  There  are  three  kinds  of  enthymeme: 

"1.  With  the  major  premise  omitted. 
"  This  enterprise  will  tend  to  increase  the  public  wealth, 
because  it  will  promote  the  general  happiness  of  the  people. 

"  2.  With  the  minor  premise  omitted. 
"  That  expedition  is  doomed  to  failure,  because  no  small 
93 


94  AN  OUTLINE  OF  LOGIC 

body  of  men  insufficiently  equipped  and  cut  off  from  their 
base  of  supplies  can  ever  reduce  so  strongly  fortified  a 
garrison. 

"  3.  With  conclusion  omitted. 

"All  members  of  that  conference  were  traitors  to  then- 
party.  And  you  were  a  member  of  that  conference.  Noth- 
ing more  need  be  said."  * 

The  reason  why  we  deal  with  incomplete  argu- 
ments seems  to  be  twofold.  A  part  may  be  omitted, 
either  because  the  assumption  is  so  obvious  that  ex- 
plicit statement  would  be  unnecessary,  not  to  say 
pedantic;  or  because  the  assumption  is  so  well  con- 
cealed that  we  are  quite  unaware  of  its  presence.  In 
the  latter  ease  it  is  evidently  rather  far-fetched  to 
say  that  the  missing  part  of  the  argument  is  carried 
along  in  the  mind.  Nevertheless,  the  argument  im- 
plies this  missing  part,  in  the  sense  that  unless  it  is 
true  the  reasoning  as  a  whole  is  not  true.  Thus  a 
person  may  argue  for  the  compulsory  arbitration  of 
labor  troubles,  on  the  ground  that  this  would  be 
much  more  economical;  and  he  may  be  unconscious 
all  the  while  that  he  is  taking  for  granted  one  of  the 
premises  of  the  argument.  If  put  into  the  form  of 
a  syllogism  the  argument  would  run  about  as  follows : 

Whatever  is  economical  may  be  enacted  into  law; 
Compulsory  arbitration  would  be  economical; 
Therefore  compulsory  arbitration  may  be  enacted  into 
law. 

*  Hibben,  Logic,  Deductive  and  Inductive,  p.   131. 


FALSE  ASSUMPTION  95 

The  major  premise  may  receive  no  mention  at  all, 
yet  unless  its  truth  is  conceded,  the  argument  falls 
to  the  ground. 

The  Definition  of  False  Assumption. — The  as- 
sumption that  is  made  unconsciously  is  naturally 
much  more  dangerous  than  the  kind  that  is  made  with 
explicit  awareness  of  the  fact.  As  the  above  illustra- 
tion shows,  it  may  be  found  that  the  premise  which 
is  thus  tacitly  assumed  is  anything  but  self-evidently 
true.  False  assumption,  or  begging  the  question,  then, 
consists  in  making  an  assumption  which  an  opponent 
would  not  grant  if  its  real  character  were  understood. 

False  Assumption,  Ambiguity,  and  Imperfect  Dis- 
junction.—  The  definition  of  false  assumption  given 
in  the  preceding  paragraph  may  be  taken  in  a  wider 
or  in  a  narrower  sense.  Taken  in  the  wider  sense, 
false  assumption  includes  both  ambiguity  and  im- 
perfect disjunction.  In  the  narrower  sense,  it  refers 
only  to  arguments  in  which  the  questionable  premise 
is  not  put  into  words,  but  is  quietly  taken  for  granted. 
In  common  usage  the  term  is  not  confined  to  argu- 
ments in  which  one  of  the  premises  is  suppressed, 
and  so  we  shall  first  discuss  false  assumption  in  rela- 
tion to  ambiguity  and  imperfect  disjunction.  It  will 
appear  that  the  fallacies  of  ambiguity  and  imperfect 
disjunction  may  also,  if  we  see  fit,  be  viewed  as  cases 
of  false  assumption. 

If  the  questionable  proposition  which  serves  as  a 
premise  contains  an  ambiguity,  the  false  assumption 
is  to  be  found  in  the  fact  that  a  certain  meaning  is 
given  to  this  proposition,  without  proof  that  this  mean- 
ing is  the  one  which  should  be  assigned  to  it.  Thus, 
if  we  should  argue  that  a  proposed  measure  (e.g.,  pro- 


96  AN  OUTLINE  OF  LOGIC 

liibition)  is  wrong,  because  it  is  an  infringement  upon 
personal  liberty,  and  all  infringements  upon  personal 
liberty  are  wrong,  it  may  be  open  to  an  opponent 
either  to  point  out  that  '  personal  liberty  '  is  an 
ambiguous  term,  having  a  wider  and  a  narrower  mean- 
ing, or  he  may  accuse  us  of  begging  the  question, 
because  we  assume  without  proof  that  the  meaning 
of  the  term  is  such  as  to  make  it  applicable  to  the 
proposed  measure.  By  what  name  the  fallacy  shall 
be  called  depends  upon  the  point  of  view  that  happens 
to  be  taken,  i.e.,  upon  the  phase  or  aspect  wThich  re- 
ceives chief  notice. 

In  case  the  debatable  proposition  contains  a  false 
disjunction,  it  may  be  said  to  beg  the  question,  because 
the  disjunction  is  offered  without  proof  that  it  is 
correct.  As  examples  we  may  take  two  arguments 
which  were  advanced  in  order  to  prove  the  common 
belief  that  every  event  has  a  cause: 

1.  Whatever  is  produced  without  a  cause  is  produced  by 
nothing,  or  in  other  words  has  nothing  for  its  cause.  But 
nothing  can  never  be  a  cause.  Hence  every  object  has  a 
real  cause  of  its  existence. 

2.  Everything  must  have  a  cause;  for  if  anything  wanted 
a  cause  it  would  produce  itself,  that  is,  exist  before  it 
existed,  which  is  impossible.* 

The  question  here  raised  is  in  both  instances  whether 
anything  can  come  into  being  without  a  cause; 
whether  a  thing  has  to  be  '  produced  '  in  order  to 
exist.     Both  arguments,  however,  assume  this  very 

*  Cf.  Hume,  Treatise  of  Human  Nature,  Part  III.,  Section  3. 


FALSE  ASSUMPTION  97 

point  by  means  of  an  imperfect  disjunction.  They 
present  various  alternative  ways  in  which  things 
might  be  supposed  to  come  into  being,  but  these 
alternatives  all  presuppose  some  kind  of  agency.  The 
first  argument  says  that  the  agency  is  either  a  '  real 
cause  '  or  a  hypostatized  abstraction  called  '  Nothing. ' 
The  second  argument  bids  us  decide  whether  a  given 
thing  was  produced  by  something  else  or  by  itself. 
In  each  case  the  disjunction  evidently  leaves  out  the 
one  alternative  that  is  under  discussion,  viz.,  whether 
things  need  any  cause  at  all  for  their  existence.  In 
other  words,  the  disjunction  presupposes  an  agency 
of  some  sort  for  every  event,  and  thus  begs  the 
question. 

False  Assumption  and  the  Syllogism. — It  was 
pointed  out  before  that  the  study  of  the  syllogism 
affords  no  protection  against  ambiguity,  other  than 
false  obversion  and  conversion,  nor  against  imperfect 
disjunction.  The  syllogism  may,  however,  be  of 
service  in  connection  with  false  assumption  in  the 
narrower  sense,  viz.,  the  false  assumption  which  in- 
volves the  suppression  of  a  premise.  This  kind  of 
fallacy  is  due  largely  to  the  fact  that  we  have  not 
acquired  sufficiently  the  habit  of  noticing  the  implica- 
tions of  our  reasoning.  The  reasoning,  as  it  stands, 
is  incomplete,  and  if  we  were  properly  critical,  we 
should  endeavor  to  complete  it.  But  this  ordinarily 
requires  practice;  and  this  practice  is  furnished,  in 
a  way,  by  the  syllogism,  since  it  accustoms  us  to  the 
requirements  of  a  complete  argument.  To  argue,  for 
example,  that  democracy  is  an  undesirable  form  of 
government,  because  it  has  certain  specified  defects, 
h  to  assume,  as  the  syllogism  helps  us  to  see,  that 


98  AN  OUTLINE  OF  LOGIC 

governments  with  such  defects  are  undesirable ;  which, 
as  a  universal  proposition,  may  well  be  open  to  doubt. 
In  short,  the  study  of  the  syllogism  tends  toward  the 
discovery  of  hidden  assumptions,  and  thus  it  makes 
for  the  elimination  of  assumptions  that  are  inde- 
fensible. 

To  criticize  our  own  arguments  and  to  unearth  their 
hidden  assumptions  seems  to  be  particularly  difficult 
if  the  matter  at  issue  is  something  that  concerns  our 
practical  interests.  We  are  prone,  in  such  circum- 
stances, to  insist  exclusively  upon  our  side  of  the 
case.  The  reason  why  we  do  not  get  our  opponent's 
point  of  view  may  be  that  we  do  not  look  for  our  own 
assumptions  and  reflect  upon  them  impartially.  The 
following  passage  from  a  daily  newspaper  exemplifies 
this  tendency : 

"  The  cause  of  the  first  strike  [Chicago  Stock  Yards, 
1903]  was  wages.  More  particularly  it  was  the  wages 
of  unskilled  laborers.  Under  the  agreement  of  last 
year  the  packers  had  been  paying  18^  cents  an  hour. 
Meanwhile  the  conditions  of  the  labor  market  had 
changed.  Hundreds  of  men  were  presenting  them- 
selves every  morning  to  request  the  opportunity  of 
working  for  16  or  even  15  cents  an  hour.  The  packers 
felt  that  it  was  unfair  to  require  them  to  pay  more 
than  the  law  of  supply  and  demand  indicated. 

"  The  argument  offered  by  the  union  ignored  the 
law  of  supply  and  demand.  It  based  itself  on  living 
conditions.  The  average  number  of  working  hours 
provided  for  unskilled  laborers  during  an  average 
week  was  said  to  be  about  forty.  Forty  hours  at  18^ 
cents  an  hour  makes  $7.40.  No  man,  said  the  union, 
could   live    decently   on    less   than   $7.40.      And   the 


FALSE  ASSUMPTION  99 

packers  could  pay  $7.40  without  seriously  reducing 
their  dividends." 

It  is  evident  that  each  side  is  making  an  assumption. 
"We  may  attempt  to  state  both  arguments  in  syl- 
logistic form,  so  as  to  bring  to  light  the  assumptions : 

1.  Wages  as  determined  by  supply  and  demand  are 
proper  wages; 

Sixteen  or  fifteen  cents  per  hour  are  wages  as  determined 
by  supply  and  demand; 

Therefore  sixteen  or  fifteen  cents  per  hour  are  proper 
wages. 

2.  Wages  as  determined  by  living  conditions  are  proper 
wages ; 

Not  less  than  eighteen  and  a  half  cents  per  hour  are 
wages  as  determined  by  living  conditions; 

Therefore  not  less  than  eighteen  and  a  half  cents  per 
hour  are  proper  wages. 

Neither  side  seems  to  criticize  its  own  assumptions, 
yet  one  at  least  must  be  wrong.  It  would  probably 
be  pretty  generally  conceded  that  both  supply  and 
demand  and  living  conditions  should  be  considered. 
If  this  is  true,  then  the  question  of  what  constitutes 
proper  wages  is  begged  by  the  assumption  that  the 
matter  is  determined  by  either  of  these  considerations 
to  the  exclusion  of  the  other. 

As  a  second  illustration  of  questionable  assumption 
we  may  consider  this  argument,  which  is  intended  to 
show  that  the  accounts  of  miracles  are  presumably 
untrustworthy : 

"  We  must  admit  that  all  probabilities  must  be 
against  miracles,  for  the  reason  that  that  which  is 
probable    cannot   by    any   possibility   be    a    miracle. 


100  AN  OUTLINE  OF  LOGIC 

Neither  the  probable  nor  the  possible,  so  far  as  man 
is  concerned,  can  be  miraculous.  The  probability 
therefore  says  that  the  writers  and  witnesses  were 
either  mistaken  or  dishonest. ' '  * 

That  '  neither  the  probable  nor  the  possible  can 
be  miraculous  '  is  perfectly  true,  if  we  determine 
probability  and  possibility  by  conformity  to  natural 
law,  as  the  writer  plainly  does.  If  we  confine  our- 
selves to  natural  law  we  must  concede  that  it  is  neither 
probable  nor  possible  that  the  dead  should  come  to 
life  or  that  water  should  be  turned  into  wine.  But 
if  we  proceed  to  say  that  miracles  are  therefore  im- 
probable, we  evidently  base  our  assertion  upon  the 
incompatibility  of  miracle  with  natural  law.  Is  this 
incompatibility  a  fair  test  of  improbability?  Since 
the  question  at  issue  is  whether  events  that  are  in- 
compatible with  natural  law  have  ever  occurred,  the 
assumption  that  such  events  are  improbable  clearly 
begs  the  question.  The  fallacy  involved  may  also  be 
classified  as  an  ambiguity.  The  term  probability  may 
be  taken  to  refer  either  to  '  ground  for  belief  '  or  to 
1  ground  for  belief  on  the  basis  of  natural  law. ' 

Two  Special  Forms  of  False  Assumption. — A. 
Reasoning  in  a  Circle. — The  fallacy  .  of  false  as- 
sumption, like  ambiguity,  presents  some  easily  recog- 
nizable forms,  which  are  of  sufficient  interest  to  en- 
title them  to  special  mention.  One  of  these  is  Reason- 
ing in  a  Circle.  It  consists  in  using  a  proposition  as 
a  premise  to  prove  a  conclusion,  and  then  at  some 
other  stage  in  the  argument  proving  this  premise  by 
means  of  the  very  conclusion  which  it  has  previously 
helped  to  establish.  In  other  words,  the  conclusion 
*  North  American  Review,  Vol.  150,  p.  332. 


FALSE  ASSUMPTION  101 

presupposes  the  premise  and  the  premise  presupposes 
the  conclusion.  In  this  way  the  thing  that  is  to  be 
proved  is  presupposed,  for  we  must  be  sure  of  the 
conclusion  before  we  have  a  right  to  use  the  premise. 

To  cite  examples  of  this  fallacy  is  usually  difficult, 
for  the  reason  that  the  fallacy  is  not  likely  to  occur 
except  in  the  course  of  a  lengthy  argument.  When  the 
argument  is  brief,  we  are  more  apt  to  see  all  the 
different  parts  at  once  and  to  notice  this  peculiar 
relation  of  the  two  propositions  that  help  to  prove 
each  other.  The  following,  however,  will  serve  as 
an  illustration: 

"  It  is  wrong  to  take  the  life  of  a  fellow  man,  for 
God  has  distinctly  commanded  us  not  to,  and  it  is 
wicked  to  disobey  his  commandments.  If  any  one 
pretends  to  doubt  that  this  commandment  really  did 
come  from  God,  I  can  only  appeal  to  his  own  con- 
science and  his  own  common  sense.  When  God  gave 
the  Commandments  to  his  people  is  it  likely  that  he 
would  have  omitted  the  most  important  of  them  all 
— a  commandment  which  only  expresses  the  natural 
feeling  of  every  normal  human  being?  '!  (Aikins, 
Logic,  p.  469.) 

If  we  state  this  argument  in  two  syllogisms  its 
circular  character  will  be  evident: 

I.  Whatever  is  forbidden  by  God  is  wrong; 

To  take  the  life  of  a  fellow  man  is  forbidden  by  God ; 
Therefore  to  take  the  life  of  a  fellow  man  is  wrong. 

II.  Whatever  is  wrong  is  forbidden  by  God; 
To  take  the  life  of  a  fellow  man  is  wrong; 
Therefore  to  take  the  life  of  a  fellow  man  is  forbidden 

by  God. 


102  AN  OUTLINE  OF  LOGIC 

The  proposition,  '  To  take  the  life  of  a  fellow  man 
is  wrong/  functions  both  as  a  conclusion  and  as  a 
premise.  We  know  that  taking  life  is  wrong  because 
it  is  forbidden  by  God,  and  we  know  that  it  is  for- 
bidden by  God  because  we  know  (through  conscience 
and  common  sense)  that  it  is  wrong.  Similar  remarks 
apply  to  the  proposition,  '  To  take  the  life  of  a  fellow 
man  is  forbidden  by  God.' 

B.  Irrelevancy,  or  Ignoring  the  Question. — A 
second  form  of  false  assumption  consists  in  proving 
something  quite  other  than  the  point  at  issue.  Thus 
"  instead  of  proving  that '  this  prisoner  has  committed 
an  atrocious  fraud,'  you  prove  that  the  fraud  he  is 
accused  of  is  atrocious:  instead  of  proving  (as  in 
the  well-known  tale  of  Cyrus  and  the  two  coats)  that 
the  taller  boy  had  a  right  to  force  the  other  boy  to 
exchange  coats  with  him,  you  prove  that  the  exchange 
would  have  been  advantageous  to  both:  instead  of 
proving  that  the  poor  ought  to  be  relieved  in  this 
way  rather  than  in  that,  you  prove  that  the  poor 
ought  to  be  relieved."     (Whately.) 

It  may  seem  a  little  strange  that  entirely  different 
questions  should  be  mistaken  for  each  other.  This 
is  less  strange,  however,  when  we  notice  how  the 
mistake  comes  about.  The  argument  that  the  ex- 
change of  coats  was  advantageous  to  both  boys,  which 
is  offered  as  a  justification  for  the  taller  boy's  pro- 
cedure in  compelling  an  exchange,  is  a  good  example. 
The  conclusion  that  the  exchange  was  for  the  good 
of  both  parties  is  relevant,  if  we  treat  it  as  a  premise 
for  a  second  conclusion.  Add  to  this  premise  the 
further  premise — which  is  not  stated  but  assumed — 
that,  '  All  exchanges  which  are  for  the  good  of  both 


FALSE  ASSUMPTION  103 

parties  are  right,'  and  we  are  enabled  to  draw  the 
required  conclusion:  '  This  exchange  was  right.' 

It  appears,  then,  that  the  conclusion, '  The  exchange 
was  advantageous,'  which  the  argument  actually 
proves  or  aims  to  prove,  is  irrelevant  only  in  the 
sense  that  it  is  incomplete.  What  is  proved  is  not 
the  point  at  issue,  but  a  proposition  which,  together 
with  a  tacit  assumption,  is  equivalent  to  the  proof 
of  the  point  at  issue.  But  if  the  assumption  is  of 
a  questionable  character,  it  requires  justification,  and 
until  this  is  furnished,  the  argument  is  irrelevant  and 
goes  for  naught. 

The  person  who  commits  the  fallacy  of  irrelevancy 
is,  of  course,  quite  unaware  of  his  error,  unless  his 
purpose  be  to  mislead.  He  does  not  see  that  the 
proposition  which  he  proves  is  related  to  the  point 
at  issue  only  through  a  questionable  assumption. 
But  in  criticizing  an  irrelevant  argument  it  is  not 
necessary  to  point  out  the  nature  of  the  assumption 
which  underlies  the  argument.  Merely  to  show  that 
what  is  proved  is  not  what  ought  to  be  proved  or 
what  is  supposed  to  be  proved,  answers  the  purpose 
of  criticism.  '  True,  but  irrelevant, '  is  often  the  most 
concise  and  effective  criticism.  "  Thus  when  in  a 
discussion  one  party  vindicates,  on  the  ground  of 
general  expediency,  a  particular  instance  of  resistance 
to  government  in  a  case  of  intolerable  oppression,  the 
opponent  may  gravely  maintain  '  that  we  ought  not 
to  do  evil  that  good  may  come  ' — a  proposition  which, 
of  course,  had  never  been  denied,  the  point  in  dispute 
being  '  whether  resistance  in  this  particular  case  were 
doing  evil  or  not.'  Or  again,  by  way  of  disproving 
the  assertion  of  the   right  of  private   judgment   in 


101  AN  OUTLINE  OF  LOGIC 

religion,  one  may  hear  a  grave  argument  to  prove 
that  '  it  is  impossible  every  one  can  be  right  in  his 
judgment.'  "  (Whately.)  The  first  of  these  argu- 
ments assumes,  as  a  second  premise,  that '  this  is  a  case 
of  doing  evil  that  good  may  come  ';  while  the  second 
takes  for  granted  that  '  if  every  one  cannot  be  right 
in  his  judgment,  then  private  judgment  should  not  be 
permitted.'  These  assumptions,  however,  are  highly 
questionable,  and  until  they  are  proved  the  arguments 
are  beside  the  question. 

In  a  similar  way  an  argument  to  prove  that  the 
compulsory  arbitration  of  labor  disputes  would  be 
economical  might  be  set  aside  as  irrelevant,  if  the 
question  were,  not  whether  arbitration  would  be  more 
economical,  but  whether  this  form  of  economy  should 
be  brought  about  by  legislative  enactment.  Again  we 
might  treat  as  irrelevant  the  proof  that  the  law  of 
supply  and  demand  requires  a  certain  scale  of  wages, 
or  that  living  conditions  determine  a  certain  minimum 
for  wages;  if  it  is  once  admitted  that  the  question 
is  by  what  standards  the  proper  scale  of  wages  is 
to  be  determined  in  a  specific  case. 

A  further  illustration  of  irrelevancy  may  be  drawn 
from  Dr.  Samuel  Johnson's  "  Taxation  no  Tyranny," 
in  which  the  writer  attempts  to  show  that  the  Amer- 
ican Colonies  had  no  right  to  rebel  against  the  system 
of  taxation  imposed  upon  them  by  the  British  govern- 
ment: 

"  A  tax  is  a  payment  exacted  by  authority  from 
part  of  the  community  for  the  benefit  of  the  whole. 
From  whom,  and  in  what  proportion,  such  payment 
shall  be  required,  and  to  what  uses  it  shall  be  applied, 
those  only  are  to  judge  to  whom  government  is  in- 


FALSE  ASSUMPTION  105 

trusted.  In  the  British  dominions  taxes  are  appor- 
tioned, levied,  and  appropriated  by  the  states  as- 
sembled in  parliament. 

"  Of  every  empire  all  the  subordinate  communities 
are  liable  to  taxation,  because  they  all  share  the  bene- 
fits of  the  government,  and  therefore  ought  all  to 
furnish  their  proportion  of  the  expense. 

"  This  the  Americans  have  never  openly  denied. 
That  it  is  their  duty  to  pay  the  costs  of  their  own 
safety  they  seem  to  admit;  nor  do  they  refuse  their 
contribution  to  the  exigencies,  whatever  they  may 
be,  of  the  British  empire;  but  they  make  this  par- 
ticipation of  the  public  burden  a  duty  of  very  un- 
certain extent,  and  imperfect  obligation,  a  duty  tempo- 
rary, occasional,  and  elective,  of  which  they  reserve 
to  themselves  the  right  of  settling  the  degree,  the 
time,  and  the  duration,  of  judging  when  it  may  be 
required,  and  when  it  has  been  performed." 

The  question  here  argued  is  that  taxes  may  be 
levied  and  apportioned  by  those  l  to  whom  government 
is  intrusted. '  Since  the  question  raised  by  the  colonies 
was  not  whether  the  government  could  impose  taxes, 
but  whether  the  colonies  rightfully  constituted  a  part 
of  the  government  (i.e.,  had  a  right  to  representation), 
the  argument  is  irrelevant  to  the  point  at  issue. 

A  subordinate  form  of  this  fallacy  is  known  in  logic 
as  the  Argumentum  ad  Hominem  or  the  Argumentum 
ad  Popidum,  according  as  it  is  directed  to  an  indi- 
vidual or  to  a  multitude.  This  fallacy  is  incurred 
whenever  an  appeal  is  made  to  emotion  or  passion 
or  prejudice,  to  the  neglect  of  the  point  at  issue. 
While  appeals  to  emotion  doubtless  have  a  legitimate 
and  necessary  function,  they  are  to  be  condemned 


106  AN  OUTLINE  OF  LOGIC 

when  they  are  offered  as  substitutes  for  argument 
and  when  by  confusing  issues  they  obscure  the  con- 
ditions of  the  situation.  In  the  plea  for  the  abolition 
of  capital  punishment  about  to  be  quoted,  the  writer 
ignores  the  main  issue,  viz.,  the  good  of  society,  and 
strives  to  arouse  religious  sentiment  by  the  presenta- 
tion of  a  consideration  which  is  essentially  irrelevant 
to  the  situation.  The  plea  asserts  that  one  considera- 
tion "  would  be  alone  a  sufficient  reason  for  rejecting 
the  extreme  penalty :  wre  mean  the  necessity  that  there 
is  for  an  admixture  of  the  element  of  mercy  in  all 
human  punishments.  Be  a  man  as  guilty  as  he  may, 
he  is  still  '  bound  with  the  cords  of  a  man  '  to  all 
mankind:  he  is  still  our  brother,  and  has  a  right, 
if  no  longer  to  our  affection,  at  least  to  our  pity.  Nay, 
if  not  for  his  sake,  at  least  for  our  own,  we  are  bound 
to  show  him  mercy.  How  shall  we  hope  for  mercy, 
rendering  none  ?  We  know  full  well  that  '  with  what 
measure  we  mete,  it  shall  be  measured  unto  us  again,' 
and  that  '  our  Heavenly  Father  will  not  forgive  us, 
unless  we  from  our  heart  forgive  every  one  his  brother 
their  trespasses.'  If  we  say  to  a  fellow  criminal 
(perhaps,  if  all  could  be  known,  not  so  intrinsically 
wicked  as  ourselves),  that  he  shall  have  no  mercy 
upon  earth,  how  can  we  hope  for  mercy  before  the 
judgment  seat  of  God?  This  is  a  solemn  considera- 
tion, but  it  is  one  on  which  we  can  rest  our  case, 
for  it  appeals  to  the  very  heart  of  Christianity,  and 
can  only  be  answered  in  one  way."  * 

*  Eclectic  Review,  July,   1849,  p.   118. 


CHAPTER  IX 
THE  PROOF  OF  UNIVERSAL  CONNECTIONS 

The  study  of  the  syllogism  has  shown  us  what  the 
relation  of  classes  must  be  in  order  that  valid  conclu- 
sions may  be  drawn.  It  assumes,  however,  that  the 
classes  with  which  it  deals  are  marked  off  with  suffi- 
cient clearness  to  warrant  assertions  that  are  applica- 
ble to  all  the  members  of  the  class.  Until  this  con- 
dition is  fulfilled  there  is  no  room  for  syllogistic 
reasoning.  But  we  have  also  seen  that  the  existence 
of  class  names  does  not  signify  that  we  know  their 
precise  import;  for  if  we  did  there  would  be  no 
ambiguity.  Class  names  may  cover  a  variety  of  things, 
so  that  a  statement  which  is  true  of  some  is  not 
necessarily  true  of  all.  "We  must  now  take  up  the 
question  in  what  way  universal  propositions  may  be 
tested,  so  as  to  make  them  available  for  purposes  of 
syllogistic  inference. 

The  question  at  issue  may  be  stated  in  either  of 
two  ways:  (a)  How  may  we  assure  ourselves  that 
all  members  of  the  class  A  possess  the  attribute  B; 
or,  (b)  How  can  we  ascertain  whether  the  attribute 
A  is  an  unfailing  sign  of  the  attribute  B.  The  differ- 
ence in  the  questions  is  the  difference  between  exten- 
sion and  intension.  We  may  ask  ourselves,  for  ex- 
ample, either  how  we  happen  to  know  that  all  men 

107 


108  AN  OUTLINE  OF  LOGIC 

are  mortal  beings,  or  how  we  know  that  the  attribute 
1  man  '  is  always  conjoined  with  the  attribute 
1  mortal.' 

To  say  that  we  know  this  from  experience  is  un- 
satisfactory, because  experience  is  too  vague  a  term. 
There  are  different  experiences,  and  we  wish  to  know 
what  kind  of  experience  it  is  that  furnishes  this  in- 
formation. No  one  would  claim  that  he  knows  this 
fact  regarding  man  from  the  personal  observation 
of  all  cases.  Nor  is  the  experience  in  question  the 
kind  of  experience  which  we  mean  when  we  say  that 
we  have  experienced  a  toothache  or  that  we  know 
from  experience  the  advantages  of  early  rising. 

Proof  by  Enumeration. — A  more  definite  answer 
is  offered  when  it  is  said  that  we  know  this  proposi- 
tion to  be  true  through  Simple  Enumeration  (Incluciio 
per  enumerationem  simplicem).  By  this  term  is 
meant  that  the  conjunction  of  '  man  '  and  '  mortality  ' 
has  been  observed  in  a  number  of  instances;  or,  to 
be  more  direct,  that  a  certain  number  of  persons 
have  been  known  to  die.  Moreover,  there  are  no 
known  exceptions  to  the  rule.  And  whenever  a  rule 
is  verified  again  and  again  in  this  way,  without  ever 
being  violated,  a  point  is  finally  reached  when  we 
may  cease  to  enumerate  individual  instances  and 
say  that  what  is  true  of  some  is  true  of  all. 

That  something  of  this  sort  occurs  in  connection 
with  propositions  like, '  all  men  are  mortal,' '  all  water 
is  II20,'  '  all  life  is  from  the  living,'  and  '  all  un- 
supported terrestrial  bodies  fall,'  seems  to  be  beyond 
dispute.  If,  therefore,  we  are  to  find  fault  with  this 
explanation  it  must  be  because  it  does  not  bring  out 
the  essential  point  that  is  involved  in  the  proof  of 


THE  PROOF  OF  UNIVERSAL  CONNECTIONS    109 

universal  connections.  The  incompleteness  of  the  ex- 
planation appears  when  we  attempt  to  state  why  ten 
cases  constitute  a  stronger  proof  than  one.  It  is 
evident  that,  in  so  far  as  the  cases  are  all  alike,  one 
is  as  good  as  a  greater  number.  Numbers,  therefore, 
can  be  of  importance  only  in  so  far  as  the  several 
instances  are  in  some  respects  different  from  each 
other.  But  what  part  the  differences  play  is  left 
unexplained. 

It  may  also  be  pointed  out  that  the  degree  of  proof 
does  not  vary  in  direct  proportion  to  the  number  of 
instances  observed.  Sometimes  an  enumeration  may 
proceed  a  long  time  without  bringing  to  light  any 
exceptions  and  yet  be  found  untrue  in  the  end.  ' '  To 
an  inhabitant  of  Central  Africa  fifty  years  ago,  no 
fact  probably  appeared  to  rest  on  more  uniform  ex- 
perience than  this,  that  all  human  beings  are  black. 
To  Europeans  not  many  years  ago,  the  proposition, 
'  All  swans  are  white, '  appeared  an  equally  unequiv- 
ocal instance  of  uniformity  in  the  course  of  nature. 
Further  experience  has  proved  to  both  that  they  were 
mistaken;  but  they  had  to  wait  fifty  centuries  for 
this  experience.  During  that  long  time,  mankind 
believed  in  an  uniformity  of  the  course  of  nature 
where  no  such  uniformity  really  existed. ' '  *  On  the 
other  hand,  a  proposition  like,  '  all  water  is  H20  ' 
may  be  established  by  relatively  few  instances.  If 
numbers  alone  were  decisive,  this  proposition  would 
be  much  more  uncertain  than  the  propositions  that 
swans  are  white  and  that  men  are  black. 

Proof  by  the  Method  of  Agreement. — While 
numbers  doubtless  contribute  something  towards  cer- 
•Mill,  System  of  Logic,  Book  III.,  Chapter  III.,  §2. 


110  AN  OUTLINE  OF  LOGIC 

tainty,  the  reason  why  they  do  so  is  that  the  different 
instances  are  all  different  from  each  other.  Thus 
men  differ  in  nationality,  in  color,  in  occupation,  in 
tastes,  in  talents,  and  in  a  thousand  other  matters 
besides.  But  all  are  mortal ;  and  so  we  conclude  that 
these  differences  have  nothing  to  do  with  mortality. 
In  other  words,  while  it  is  true  that  numbers,  merely 
as  numbers,  do  not  prove  anything,  yet  in  fact  the 
gathering  of  instances  does  tend  towards  proof,  be- 
cause it  sifts  out  the  essential  from  the  accidental. 
"Wherever  we  find  the  attribute  '  man  '  we  have  the 
attribute  '  mortal, '  however  much  the  other  attributes 
may  vary.  By  viewing  '  man  '  in  diverse  contexts 
or  circumstances,  we  find  that  these  may  be  ignored. 
If,  therefore,  we  wish  to  prove  a  universal  connection, 
we  must  select  our  cases  so  as  to  vary  the  circum- 
stances as  much  as  possible.  The  process  is  a  process 
of  elimination.  We  rid  ourselves  of  those  circum- 
stances in  which  our' cases  differ,  in  order  to  isolate 
the  circumstance  in  which  they  all  agree.  If  we  find 
that  all  the  circumstances  can  be  varied,  except  one, 
we  are  entitled  to  conclude  that  this  circumstance 
in  which  all  the  cases  agree  is  an  unfailing  sign  of 
the  attribute  in  question;  and  the  method  by  which 
this  conclusion  is  established  may,  therefore,  be  called 
the  Method  of  Agreement. 

In  the  application  of  this  method,  the  number  of 
cases  necessary  for  proof  depends  upon  the  extent 
to  which  they  are  different  from  one  another.  The 
method  requires  a  sufficient  number  to  vary  all  the 
irrelevant  circumstances,  whether  that  number  be 
great  or  small.  The  following  is  a  statement  of  the 
method:  //  two  or  more  instances  of  the  phenomenon 


THE  PROOF  OF  UNIVERSAL  CONNECTIONS    111 

under  investigation  have  only  one  circumstance  in 
common,  the  circumstance  in  which  alone  all  the  in- 
stances agree  is  an  unfailing  sign  or  correlate  of  the 
given  phenomenon* 

The  conclusion,  then,  to  which  we  are  led  is  that 
enumeration  as  such  is  not  a  form  or  method  of  proof. 
The  mere  accumulation  of  instances  does  not  con- 
tribute to  the  support  of  an  inference.  Enumeration 
is  in  itself  merely  a  tool  in  the  hands  of  the  method 
which  seeks  to  prove  a  universal  by  varying  all  the 
circumstances  that  do  not  constitute  a  part  of  the 
universal  connection.  This  function  of  enumeration, 
however,  has  at  times  been  misconceived.  Thus  Jevons 
says  that  "  An  Induction,  that  is  an  act  of  inductive 
reasoning — [reasoning  from  particular  instances  to  a 
universal] — is  called  perfect,  when  all  the  possible 
cases  or  instances  to  which  the  conclusion  can  refer, 
have  been  examined  and  enumerated  in  the  prem- 
ises. ' '  f  That  all  the  apostles  were  Jews,  that  all 
the  months  in  the  year  contain  less  than  thirty-two 
days,  and  that  all  the  known  planets  revolve  about 
the  sun,  would,  from  this  standpoint,  be  considered 
perfect  inductions,  because  all  the  cases  in  question 
have  been  duly  examined  and  enumerated.     On  the 

*  This  method,  as  formulated  by  Mill  (cf.  System  of  Logic, 
Bk.  III.,  Ch.  VIII.,  §1),  was  intended  by  him  as  an  instru- 
ment for  the  testing  of  causal  connections.  As  here  used  its 
function  is  to  prove  universal  connections,  i.  e.,  connections 
in  which  A  is  an  invariable  sign  of  B.  For  this  reason,  the 
statement  of  the  method,  as  just  given,  varies  slightly  from 
Mill's  formulation.  The  study  of  causal  connections,  (unless 
we  mean  '  total '  and  not  '  partial '  cause),  is  a  different  matter 
from  that  of  universal  connections,  and  so  it  falls  more  properly 
under  a  different  method,  as  will  be  shown  in  the  succeeding 
chapter. 

f  Lessons  in  Logic,  p.  212. 


112  AN  OUTLINE  OF  LOGIC 

other  hand,  propositions  like  '  All  men  are  mortal,' 
and  '  All  water  is  H20, '  are  called  by  the  same  writer 
imperfect  inductions,  because  there  is  no  certainty 
that  future  cases  will  be  like  those  already  known. 
It  may  be  argued,  however,  that  this  '  perfect  in- 
duction '  is  not  inference  at  all,  but  merely  a  summa- 
tion of  instances.  Since  we  are  concerned,  not  with 
the  summation  of  instances,  but  with  an  underlying 
law,  we  must  resort  to  analysis.  The  proof  for  the  law 
must  be  furnished  by  the  method  which  varies  all  the 
irrelevant  details,  i.e.,  by  the  Method  of  Agreement. 

The  Principle  of  Uniformity. — The  principle 
that  underlies  this  method  may  be  stated  as  follows: 
Any  relation  is  universal  if  all  the  circumstances  ac- 
companying the  related  facts  may  be  varied  without  a 
change  in  the  relation  itself.  The  term  relation  is  here 
used  in  a  very  wide  sense.  A  relation  ' '  exists  between 
two  facts  whenever  the  mind  can  at  once  distinguish 
the  facts  as  two,  and  at  the  same  time  attend  to  them 
together  and  assert  something  of  them  considered  to- 
gether. ' '  *  Thus  the  proposition  '  all  men  are  mortal  ' 
distinguishes  between  '  man  '  and  '  mortal  '  and  as- 
serts the  relation  of  coexistence  between  them.  This 
principle  is  frequently  called  the  uniformity  of  nature. 
It  means  that  nature  behaves  the  same  way  under  the 
same  conditions;  or  that  the  unobserved  is  the  same 
in  kind  as  the  observed.  On  the  basis  of  this  prin- 
ciple we  are  enabled  to  make  assertions  about  facts 
that  have  never  come  within  the  range  of  our  direct 
experience. 

Uniformity  as  a  Postulate. — The  question  has  been 
debated  how  it  happens  that  we  make  the  assump- 
*  Hobhouse,  Theory  of  Knowledge,  p.  271. 


THE  PROOF  OF  UNIVERSAL  CONNECTIONS    113 

tion  that  nature  is  uniform.  The  term  postulate  sig- 
nifies that  the  uniformity  of  nature  is  a  presupposi- 
tion of  reasoning,  in  the  sense  that  its  truth  is  nec- 
essarily taken  for  granted,  whether  consciously  or 
unconsciously,  before  reasoning  can  begin  at  all.  We 
reason  as  though  the  principle  were  true,  simply 
because  we  are  built  that  way.  It  has  been  held, 
however,  that  uniformity  is  itself  an  inference  and 
not  a  presupposition.  We  first  observe,  it  is  said,  that 
in  a  given  number  of  instances  A  and  B  are  related 
in  a  certain  way,  and  this  leads  us  to  infer  that  they 
will  be  related  in  the  same  way  in  the  future.  When 
a  number  of  particular  uniformities  have  been  thus 
obtained,  we  take  a  further  step  and  infer  that  all 
nature  is  uniform.  This  inference  is  conceded  to  be 
merely  probable,  since  we  cannot  prove  that  no  ex- 
ceptions will  ever  occur ;  but  whether  certain  or  merely 
probable,  the  principle  must  be  suggested  by  ex- 
perience, and  is  not  a  presupposition  that  is  present 
from  the  start.* 

This  argument  gains  plausibility  from  the  fact  that 
it  assumes  what  it  attempts  to  prove.  A  and  B  have 
always  happened  together  in  the  past,  it  is  said ;  there- 
fore they  will  happen  together  in  the  future.  But 
that  A  and  B  will  be  related  in  the  future  as  they 
have  been  related  in  the  past,  can  be  inferred  only 
if  we  take  for  granted  that  the  future  will  be  like 
the  past,  i.e.,  if  we  postulate  the  uniformity  of  nature. 
Until  this  assumption  is  made,  no  amount  of  ex- 
perience can  furnish  a  basis  for  the  expectation  of 
future  events.  This  appears  if  we  state  the  argument 
in  the  form  of  a  syllogism: 
*  Cf.  Mill,  System  of  Logic,  Book  III.,  Chapters  III.  and  XXI. 


114  AN  OUTLINE  OF  LOGIC 

Things  that  have  always  happened  together  in  the  past 
will  happen  together  in  the  future; 

A  and  B  are  things  that  have  always  happened  together 
in  the  past; 

Therefore  A  and  B  are  things  that  will  happen  together 
in  the  future. 

It  is  evident  that  the  major  premise  is  merely  a 
rough  statement  of  the  law  of  uniformity.  We  may 
therefore  conclude  that  the  uniformity  of  nature  is 
an  assumption  which  does  not  wait  upon  experience, 
but  which  is  present  from  the  start,  and  which  can 
be  justified  only  by  its  results.* 

The  tendency  to  universalize  the  relations  that  come 
under  our  notice  is  a  part  of  our  mental  make-up. 
We  do  not  learn  to  universalize;  but  what  we  learn 
is  to  universalize  more  cautiously.  Our  natural  dis- 
position is  to  ignore  the  concomitant  details.  Popular 
superstitions  are  a  flagrant  example.  The  belief  that 
Friday  is  an  unlucky  day,  that  dreaming  of  a  fire 
foreshadows  a  death  in  the  family,  etc.,  may  have  its 
basis  in  nothing  further  than  a  coincidence.  The 
two  facts  have  been  observed  together  and  the  relation 
is  promptly  universalized.    Even  if  there  is  a  genuine 

*  That  the  principle  of  uniformity  appears  as  our  major 
promise  whenever  we  throw  our  reasoning  into  the  form  of  a 
syllogism,  Mill  himself  affirms.  His  belief  that  particular 
uniformities  come  first  and  that  these  form  the  basis  for 
our  he] iof  in  the  general  principle  of  uniformity  is  apparently 
determined  by  the  fact  that  we  first  become  acquainted  with 
particular  uniformities  and  that  these  then  enable  us  to 
formulate  the  general  principle  of  uniformity.  This  is  doubt- 
less true,  but  is  altogether  irrelevant.  The  order  in  which 
things  emerge  into  consciousness  is  one  thing,  the  implication 
of  inference  Is  quite  another.  The  general  principle  of  uni- 
formity is  implied  in  the  sense  that,  unless  its  truth  is 
granted,  the  inference  to  a  particular  uniformity  is  fallacious. 


THE  PROOF  OF  UNIVERSAL  CONNECTIONS    115 

connection,  this  disregard  of  concomitants  may  ap- 
pear. Hence  it  is  found  necessary  to  qualify  many 
early  generalizations.  Sparks  will  explode  powder — 
except  when  the  powder  is  damp ;  dogs  are  amiable — 
except  when  eating;  strangers  are  truthful — except 
when  they  have  an  end  to  attain;  horses  are  docile — 
except  when  frightened,  etc.  These  qualifications  ex- 
press a  tardy  recognition  of  accompanying  circum- 
stances that  were  previously  neglected;  or,  to  state 
the  same  thing  differently,  they  indicate  a  realization 
that  the  facts  between  which  the  relation  obtains  are 
more  complex  than  was  first  supposed. 

The  Impossibility  of  Varying  all  Irrelevant  Cir- 
cumstances.—  It  has  already  been  shown  that  the 
number  of  instances  is  less  important  for  the  proof 
of  a  universal  than  the  character  of  the  instances 
as  representative  of  their  various  kinds.  If  all  the 
kinds  within  the  class  are  represented,  the  inference 
from  some  to  all  is  justified,  whether  the  number  of 
representative  instances  be  few  or  many.  The  in- 
ference that  all  men  are  black  might  be  based  on 
extensive  observation;  but  it  is  wrong,  because  all 
kinds  are  not  included  in  the  observation.  Before 
we  can  reason  from  some  to  all,  we  must  have  grounds 
for  thinking  that  if  any  other  kinds  existed  we  should 
know  about  them. 

It  must  be  recognized,  however,  that  this  form  of 
proof  implies  an  ideal  to  which  it  is  impossible  to 
attain  in  practice.  The  instances  from  which  we 
reason  must  be  representative  (i.e.,  every  '  kind  ' 
within  the  class  must  be  represented),  because  we 
wish  to  vary  all  the  circumstances  except  one.  But 
we  never  know   exhaustively   what  all  the   circum- 


116  AN  OUTLINE  OF  LOGIC 

stances  of  a  given  case  may  be.  If  all  the  circum- 
stances of  any  fact  were  completely  known,  we  should 
be  omniscient,  because  every  fact  in  the  universe 
forms  a  part  of  the  environment  of  every  other  fact. 
If,  therefore,  we  were  to  try  seriously  to  vary  all 
the  circumstances  but  one,  as  the  Method  of  Agree- 
ment demands,  our  enumeration  would  have  to  in- 
clude every  case  in  existence,  and  even  then  it  would 
fall  short  of  the  ideal.  Every  case  is  in  some  respects 
different  from  every  other,  and  so  might  be  considered 
as  in  some  respect  a  new  '  kind. '  We  cannot  eliminate 
all  differences  without  considering  all  instances,  and  to 
consider  them  all  is  impossible.  How,  then,  can  we 
ever  justify  the  inference  from  some  to  all?  It  seems 
plain  that  our  method,  as  here  formulated,  makes  an 
impossible  demand. 

For  a  concrete  illustration  of  this  difficulty  we  may 
turn  again  to  the  proposition,  '  all  men  are  mortal.' 
We  do  not  know  in  detail  the  conditions  that  deter- 
mine mortality.  We  have  found,  to  be  sure,  that 
men  are  mortal,  irrespective  of  nationality,  race,  and 
similar  conditions.  But  it  is  impossible  to  show  that 
no  combination  of  circumstances,  such  as  diet,  occupa- 
tion, and  hygienic  conditions  in  general  can  ever 
occur  that  will  enable  a  man  to  live  forever.  It  might, 
therefore,  be  argued  that  we  cannot  infer  mortality 
in  any  given  case,  until  we  have  made  sure  that  this 
unique  combination  of  circumstances  is  not  realized 
in  this  particular  case.  If  we  once  grant  that  every 
individual  is  unique,  i.e.,  is  a  new  '  kind, '  the  possibility 
presents  itself  that  this  uniqueness  may  in  any  par- 
ticular instance  be  the  very  condition  which  is  nec- 
essary for  perpetual  existence. 


THE  PROOF  OF  UNIVERSAL  CONNECTIONS    117 

Reasonable  Doubt. —  The  difficulty  here  involved 
is  met,  both  in  practical  life  and  in  theoretical  matters, 
by  reference  to  what  is  known  in  debate  as  the  burden 
of  proof.  It  is  possible  in  any  situation  that  some- 
thing important  has  been  overlooked.  If  this  possi- 
bility were  a  sufficient  ground  for  doubt,  then  we 
could  never  make  any  inferences.  But  while  this 
possibility  is  not  denied,  we  ask  in  turn  what  reason 
there  is  to  suppose  that  there  are  any  exceptions  to 
the  rule.  Unless  there  is  a  specific  reason  to  the 
contrary,  we  assume  all  the  circumstances  accompany- 
ing A  and  B  to  be  irrelevant.  Other  men  have 
died;  is  there  any  ground  for  thinking  that  this 
man  is  different  in  any  essential  respect  ?  If  no  such 
ground  can  be  indicated,  i.e.,  if  there  are  no  accom- 
panying circumstances  which  would  naturally  make 
us  suppose  that  the  present  case  is  an  exception,  the 
doubt  whether  the  rule  applies  is  gratuitous.  The 
doubt  is  then  without  a  basis  or  motive.  The  nature 
of  an  unreasonable  or  unmotivated  doubt  will  appear 
more  fully  as  we  proceed,  but  as  a  provisional  defini- 
tion we  may  say  that  it  is  a  doubt  which  is  unable 
to  point  to  an  essential  fact  as  its  basis.*  Of  this  char- 
acter would  be  the  doubt  whether  this  particular  man 
is  mortal.  The  person  who  doubts  the  rule  is  required 
to  show  why  he  thinks  that  any  given  case  constitutes 
an  exception.  If  no  reasons  are  forthcoming,  the 
doubt  is  set  aside,  because  unmotivated  doubt  serves 
no  other  purpose  than  to  paralyze  thought  and  action. 
If  such  doubt  is  to  be  considered,  no  rule  can  be 
depended  upon,  i.e.,  any  particular  case  may  be  an 

*  A  more  complete  definition  of  reasonable  doubt  is  given  in 
Chapter  XI,  p.  160. 


118  AN  OUTLINE  OF  LOGIC 

exception.  Before  we  give  up  all  chance  to  know 
and  to  act,  we  must  have  something  better  than  an 
unmotivated  doubt. 

We  may  sum  up,  then,  by  saying  that  to  establish 
a  universal  proposition  it  is  of  value  to  have  many 
eases,  because  the  cases  serve  to  vary  the  circum- 
stances. Ideally  all  the  circumstances  that  are  acci- 
dental should  be  varied,  in  order  to  show  that  the 
remaining  ones  are  universally  related.  But  since 
this  is  impossible  in  practice,  the  circumstances  are 
varied  as  much  as  possible,  and  then  appeal  is  made 
to  the  principle  that  all  doubt  must  be  motivated. 
If  we  can  '  see  no  reason  to  believe  '  that  any  given 
case  constitutes  an  exception,  the  rule  is  provisionally 
accepted  as  of  universal  validity.  We  do  not  vary 
all  irrelevant  circumstances,  but  only  those  concerning 
which  there  is  room  for  motivated  doubt. 

Conversion. — An  apparent  difficulty  remains  to  be 
considered.  The  principle  of  uniformity  says  that  any 
relation  is  universal  if  there  are  no  accompanying  cir- 
cumstances which  make  a  difference.  If,  therefore,  the 
relation  A — B  is  found  to  be  universal,  A  must  be 
an  invariable  sign  of  B,  and  B  must  be  an  invariable 
sign  of  A.  A  relation  is  not  universal,  unless  the 
two  facts  concerned  always  go  together.  But  this 
seems  to  conflict  with  the  facts.  It  is  true,  of  course, 
that  from  '  man  '  we  can  infer  '  mortal,'  but  it  is 
by  no  means  equally  true  that  from  '  mortal  '  we  can 
infer  '  man.'  The  inference  from  A  to  B  may  be 
warranted  universally,  but  not  the  inference  from  B 
to  A.  As  was  shown  previously,  universal  affirmative 
propositions  are  not  amenable  to  simple  conversion. 

The  reason  for  this  apparent  discrepancy  between 


THE  PROOF  OF  UNIVERSAL  CONNECTIONS    119 

the  principle  of  uniformity  and  the  actual  relation 
between  the  subject  term  and  the  predicate  term  of 
our  universal  propositions  is  that  in  practice  we  fre- 
quently fail  to  analyze  our  predicate  term  far  enough 
to  make  the  relation  of  A  and  B  reversible.  For 
example,  a  person  who  is  drowned  is  dead,  but  we 
cannot  infer  that  one  who  is  dead  must  have  met 
death  by  drowning.  And  yet  it  is  just  as  safe  to 
infer  from  '  dead  '  to  '  drowned,'  if  we  happen  to 
know  the  peculiar  effects  that  are  produced  by  drown- 
ing. In  other  words,  drowning  not  only  produces 
death  but  a  peculiar  kind  of  death ;  and  if  this  peculiar 
nature  is  duly  considered,  the  relation  is  strictly  re- 
versible. Similarly,  the  attribute  mortality  is  in 
strictness  different  in  the  case  of  men  and  the  lower 
animals. 

We  merely  state  the  same  thing  in  different  lan- 
guage if  we  say  that  we  vary  the  circumstances  in 
order  to  determine  that  '  man  '  always  signifies 
'  mortal,'  but  we  do  not  similarly  vary  the  circum- 
stances in  order  to  ascertain  whether  a  particular 
kind  of  mortality  always  signifies  '  man.'  The  latter 
does  not  happen  to  be  a  matter  of  interest  to  us 
at  the  time.  We  simply  note  the  general  attribute 
'  mortal  ';  we  do  not  stop  to  determine  more  pre- 
cisely what  peculiar  kind  of  mortality  it  is  that  is 
universally  related  to  man,  independently  of  accom- 
panying circumstances. 

Mathematical  Propositions. —  Before  we  leave  this 
subject,  some  consideration  should  be  given  to  mathe- 
matical propositions,  which  seem  to  constitute  an  ex- 
ception to  our  conclusions  regarding  universal  con- 
nections.   That  l-fl=2,  for  example,  is  undisputed, 


120  AN  OUTLINE  OF  LOGIC 

nor  do  we  concede  the  possibility  of  exceptions.  Uni- 
versals  of  this  kind  seem  to  differ  from  others,  both 
in  degree  of  certainty  and  in  their  independence  of 
concrete  experience.  These  universals  represent  to 
us  ideal  certainty,  and,  moreover,  they  seem  to  be 
established  by  a  method  other  than  that  of  varying 
all  the  irrelevant  circumstances. 

A  closer  comparison,  however,  of  these  with  other 
universals  enables  us  to  discover  a  family  resemblance. 
It  is  true  that  mathematical  universals  ordinarily  pos- 
sess greater  certainty  and  that  the  Method  of  Agree- 
ment is  less  in  evidence;  but  the  difference,  after  all, 
between  them  and  other  universals  is  merely  a  differ- 
ence in  subject-matter,  not  a  difference  in  the  form 
of  proof.  In  the  first  place,  the  universals  of  mathe- 
matics are,  like  all  other  universals,  dependent  upon 
experience.  In  order  to  know  that  one  unit  added 
to  another  unit  gives  a  whole  of  two  units,  we  must 
have  some  experience  with  the  world  of  fact.  Units 
are  merely  abstractions,  and  before  they  can  be  ob- 
tained, we  must  have  things  from  which  to  abstract. 
These  things  may  be  anything  we  please,  from  a 
concrete  object  such  as  a  tree,  to  an  aggregate  like 
a  mob,  or  something  intangible  like  a  philosophical 
system  or  a  moral  aspiration.  Whatever  the  things 
in  question  may  be,  they  possess  from  one  point  of 
view  the  character  of  unity  and  may  be  treated  as 
units.  This  character  of  unity  is  isolated  by  abstrac- 
tion. After  our  units  are  once  obtained,  they  main- 
tain their  identity  and  integrity  through  our  deter- 
mination that  each  unit  shall  be  a  unit,  a  whole  unit, 
and  nothing  but  a  unit,  as  long  as  our  calculation 
is  in  progress.    "  How  could  our  notion  that  one  and 


THE  PROOF  OF  UNIVERSAL  CONNECTIONS    121 

one  are  eternally  and  necessarily  two  ever  maintain 
itself  in  a  world  where  every  time  we  add  one  drop 
of  water  to  another  we  get  not  two  but  one  again? 
in  a  world  where  every  time  we  add  a  drop  to  a 
crumb  of  quicklime  we  get  a  dozen  or  more? — had 
it  no  better  warrant  than  such  experience?  At  most 
we  could  then  say  that  one  and  one  are  usually  two. 
Our  arithmetical  propositions  would  never  have  the 
confident  tone  which  they  now  possess.  That  confident 
tone  is  due  to  the  fact  that  they  deal  with  abstract 
and  ideal  numbers  exclusively. ' '  * 

It  is  evident,  then,  that  the  proposition  1  +  1  =  2 
is  true  only  in  so  far  as  the  units  which  constitute  the 
sum  maintain  their  respective  identities.  By  '  two  '  we 
mean  the  whole  which  results  when  one  unit  is  con- 
sidered together  with  another  unit,  while  at  the  same 
time  each  of  the  units  receives  separate  recognition. 
But  what  sort  of  a  whole  results  when  the  units  are 
treated  in  this  way?  Unless  we  know  this,  '  two  '  is 
merely  an  empty  name,  like  the  algebraic  x.  In  order 
to  know  the  nature  of  the  whole  in  question,  we  must 
get  our  clue  in  some  way  from  immediate  experience. 
The  ultimate  meaning  of  '  two,'  therefore,  is  the 
unique  experience  of  duality  which  results  whenever 
the  units  are  presented  in  the  way  just  indicated. 

This  peculiar  experience  of  duality,  we  find,  results 
whenever  two  things  are  presented  together,  while  at 
the  same  time  they  are  distinguished  from  each  other. 
So  far  as  can  be  discovered,  the  color,  size,  spatial 
relations,  or,  in  short,  all  the  attributes  of  things,  save 
the  attribute  of  unity,  are  quite  irrelevant  to  the  result. 
That  is  to  say,  these  other  attributes  can  all  be  varied 
*  James,  Psychology,  Vol.  II.,  p.  655. 


122  AN  OUTLINE  OF  LOGIC 

without  affecting  the  relation  in  question.  It  seems, 
then,  that  the  proposition  1  +  1  =  2  depends  for  its 
proof  upon  the  elimination  of  irrelevant  circum- 
stances, an  elimination  which  is  accomplished  by  means 
of  the  Method  of  Agreement. 

In  objection  to  this  conclusion  the  point  may  be 
raised  that  in  the  case  of  other  universals  it  is  pos- 
sible to  imagine  exceptions,  while  this  is  not  possible  in 
mathematics.  We  can  easily  imagine  an  unsupported 
body  remaining  stationary  a  few  feet  from  the  ground ; 
we  are  quite  unable  to  imagine  that  two  objects,  if 
presented  in  the  manner  described  above,  should  give 
us  the  experience  of  '  three.'  This  difference,  how- 
ever, is  easily  explained.  Mathematical  propositions 
apply  not  only  to  physical  objects,  but  to  mental  ob- 
jects as  well.  An  imagined  violation  of  the  law  of 
gravity  would  not  constitute  an  actual  violation; 
whereas  an  imagined  violation  of  the  law  of  numbers 
would,  from  the  nature  of  the  case,  be  a  real  violation. 
The  law  of  numbers  is  supposed  to  hold  good  for  all 
kinds  of  countable  things  whatsoever,  whether  these 
things  be  real  or  imaginary.  If,  therefore,  an  excep- 
tion could  be  imagined,  this  very  fact  would  prove  the 
universal  to  be  untrue.  To  conclude,  then,  the  uni- 
versals which  constitute  the  foundations  of  mathe- 
matics are,  according  to  this  view,  the  same  in  kind  as 
all  other  universals.  The  difference  between  them  is 
not  a  difference  in  the  method  of  verification,  but  a 
difference  in  scope  and  in  the  readiness  with  which  the 
subject-matter  lends  itself  to  our  method  of  treatment. 


CHAPTER  X 
THE  PROOF  OF  CAUSAL  CONNECTIONS 

We  have  seen  that  a  relation  is  universal  if  none 
of  the  accompanying  circumstances  affect  it  in  any 
way.  Universal  propositions,  however,  are  relatively 
few  in  number.  Many  propositions — of  which  popular 
maxims  furnish  examples — are  general  but  not  uni- 
versal; they  apply  to  a  certain  indeterminate  number 
of  a  class,  but  not  to  the  whole.  Or,  since  universals 
are  commonly  called  generalizations,  we  may  dis- 
tinguish these  others  as  '  loose  '  or  '  rough  '  generaliza- 
tions. They  lack  the  quality  of  universality,  because 
they  are  abstract,  i.e.,  because  they  point  out  only  a 
part  of  the  circumstances,  conditions,  or  attributes  to 
which  the  predicate  in  question  is  universally  related. 
'  Haste  makes  waste,'  is  a  proposition  which  states 
only  a  part  of  the  truth.  Haste  by  itself  is  not  uni- 
versally accompanied  by  waste,  but  haste  plus  certain 
circumstances,  or  haste  under  certain  unspecified  con- 
ditions. The  total  fact  that  is  always  accompanied 
by  waste  is  a  complex  affair,  of  which  haste  is  only 
a  part  or  element. 

Causation. — It  is  one  of  the  most  common  ex- 
periences of  life  that  if  a  certain  circumstance  or 
condition  be  added  to  certain  other  circumstances  or 
conditions,  a  certain  result  will  occur  which  does 
not  occur  as  long  as  these  other  circumstances  are 

123 


124  AN  OUTLINE  OF  LOGIC 

left  to  themselves.  Such  a  circumstance  is  called  a 
cause.  In  this  sense  haste  is  the  cause  of  waste.  In 
the  common  usage  of  the  term,  a  cause  is  only  a 
part  of  the  totality  of  conditions  with  which  the  result 
is  invariably  conjoined.  Sometimes,  indeed,  we  speak 
of  this  totality  of  conditions  as  the  cause  of  an 
event,  in  which  case  we  are  apt  to  designate  it  as 
the  total  or  complete  cause.  Usually,  however,  the 
term  cause  is  used  for  that  circumstance  or  condition 
which  is  the  immediate  occasion  of  the  phenomenon 
or  event. 

Two  things  require  notice  at  the  outset.  In  the 
first  place,  the  study  of  causal  connections  (unless 
by  cause  we  mean  '  total  cause  '),  is  not  concerned 
with  the  proof  of  universal  propositions,  i.e.,  general- 
izations which  admit  of  no  exceptions,  but  with  the 
analysis  of  the  fact  A  which  is  universally  conjoined 
with  the  fact  B.  The  fact  A  being  complex,  we  try 
to  ascertain  what  constituents  are  involved.  If  all  these 
constituents  can  be  analyzed  out,  we  are  in  a  position 
to  advance  a  universal  proposition,  viz.,  that  when- 
ever all  these  conditions  are  realized,  a  certain  result 
will  invariably  occur.  The  study  of  causation  is  the 
study  of  the  elements  involved  in  universal  connec- 
tions. It  will  be  noticed,  therefore,  that  in  the  study 
of  causation  the  principle  of  uniformity  is  presup- 
posed. As  long  as  some  only  of  these  constituents  are 
found,  we  must  be  content  to  say  that  these  con- 
stituents tend  to  produce  this  result,  or  that  they  are 
a  cause  of  this  result,  or  that  they  will  produce  this 
result  other  things  equal.  In  this  way  propositions 
originate  which  are  general  but  not  universal;  and, 
as  we  shall  see  more  fully  later  on,  they  are  of  great 


THE  PROOF  OF  CAUSAL  CONNECTIONS   125 

importance  in  the  proof  of  particular  facts.  In  the 
second  place,  we  should  notice  that,  while  in  the 
study  of  classes  and  of  universal  propositions  we  tend 
to  emphasize  resemblances  rather  than  differences,  the 
reverse  is  true  when  we  pass  on  to  the  consideration 
of  causation.  We  can  discover  causes  only  by  noticing 
the  difference  between  those  cases  in  which  the  cause 
is  present  and  those  in  which  it  is  not.  But  as  was 
said  before,  resemblance  and  difference  imply  each 
other.  While  one  may  be  emphasized  more  than  the 
other,  neither  one  is  ever  in  sole  possession  of  the 
field. 

Group  Comparisons. — It  was  stated  just  now  that 
we  analyze  out  causal  connections  in  order  to  ascertain 
the  constituents  of  the  total  fact  A,  i.e.,  in  order 
to  differentiate  between  those  circumstances  which 
are  connected  with  the  result  and  those  which  are 
accidental.  Thus,  the  flame  that  explodes  the  powder 
is  causally  connected  with  the  result,  while  the  color 
of  the  burning  match  is  not.  But  it  may  be  a  matter 
of  considerable  difficulty  to  ascertain  whether  a  given 
circumstance  is  causally  connected  with  the  result  or 
is  merely  accidental.  This  difficulty  may  be  made 
clear  by  an  example.  It  has  long  been  a  subject  of 
debate  whether  vaccination  is  causally  connected  with 
immunity  from  smallpox.  It  may  be  granted  at  once 
that  vaccination  is  not  the  '  total  cause  '  of  such 
immunity.  At  best  it  is  a  cause  of  immunity  in  con- 
junction with  other  conditions,  for  people  who  are 
vaccinated  are  sometimes  taken  with  the  disease. 
Vaccination,  then,  is  not  more  than  a  part  of  the 
total  cause.  But  is  it  even  this?  Is  it  causally  re- 
lated at  all? 


12G  AN  OUTLINE  OF  LOGIC 

The  question  is  pertinent  because  there  is  involved 
no  universal  rule.  Some  persons  who  have  been  vac- 
cinated are  attacked  by  the  disease,  while  others  who 
have  not  been  vaccinated  remain  exempt.  It  is  easy 
indeed  to  ascribe  the  credit  to  vaccination  wThen  a 
vaccinated  person  escapes  the  disease,  and  to  make 
appeal  to  fortuitous  circumstances  when  the  unvac- 
cinated  person  is  equally  fortunate,  but  to  do  so  is  to 
assume  the  point  at  issue;  it  does  not  prove  that  the 
connection  is  anything  more  than  accidental  con- 
junction. The  vaccination  may  have  been  of  as  little 
protection  to  the  person  concerned  as  the  color  of  his 
hair  or  his  opinions  on  Italian  art. 

If  we  were  confined  to  the  consideration  of  indi- 
vidual cases  it  would  frequently  be  impossible  to 
arrive  at  a  conclusion.  But  a  conclusion  may  be 
possible  if  we  group  our  cases  into  classes.  In  the 
present  instance  we  should  form  two  classes,  the  one 
consisting  of  the  vaccinated,  the  other  of  the  un- 
vaccinated.  Now  if,  instead  of  comparing  individuals, 
we  compare  these  two  groups,  we  are  likely  to  fare 
much  better.  It  is  true  that  in  the  group  of  the 
vaccinated  there  may  be  many  who  were  taken  with 
the  disease,  while  in  the  other  group  there  are  many 
who  remained  in  good  health.  But  which  group  as 
a  group  can  make  the  better  showing?  If  we  should 
find  that  among  the  unvaccinated  the  rate  of  attack 
is  much  greater  than  among  the  vaccinated,  we  should 
take  this  as  evidence  that  there  is  a  causal  relation 
between  vaccination  and  immunity  from  smallpox. 

In  the  above  illustration  we  start  from  the  alleged 
cause— vaccination— and  proceed  towards  the  alleged 
effect_immunity.     On  occasion,  however,  it  may  be 


THE  PROOF  OF  CAUSAL  CONNECTIONS   127 

equally  easy  to  move  in  the  opposite  direction.  City 
authorities,  for  example,  may  first  have  their  attention 
called  to  a  sudden  increase  in  the  death  rate  in  the 
city  or  in  some  part  of  the  city,  and  by  the  comparison 
of  different  groups  this  fact  may  then  be  found  to  be 
conjoined  with  a  change  in  the  water  supply  or  with 
the  introduction  of  milk  from  a  new  source.  The 
groups  compared  may  be  the  population  of  the  entire 
city  for  this  year  or  this  period,  as  compared  with 
the  population  for  some  previous  period,  or  it  may 
be  the  population  of  a  certain  ward  or  section  as 
compared  with  the  rest  of  the  city.  This  procedure 
is  sometimes  known  as  group  comparisons,  and  it  is 
fundamental  to  the  science  of  statistics.  It  is  applica- 
ble to  a  wide  variety  of  subjects.  It  may  be  used, 
for  example,  to  prove  that  there  is  a  causal  connection 
between  the  failure  of  crops  and  crime,  between  north 
winds  and  cool  weather,  between  drinking  coffee  and 
sleeplessness,  etc.  Moreover,  a  group  may  consist  of 
many  different  individuals,  as  when  we  compare  the 
vaccinated  with  the  unvaccinated,  or  it  may  consist 
of  different  events  occurring  in  connection  with  the 
same  individual,  as  when  we  conclude  that  coffee  is 
the  cause  of  our  sleeplessness.  Group  comparisons, 
moreover,  may  sometimes  establish  causal  connections, 
as,  e.g.,  between  poverty  and  drink,  but  without  deter- 
mining which  is  cause  and  which  effect,  because  the 
facts  are  not  presented  in  a  temporal  order. 

Forms  of  Group  Comparison. — While  group 
comparisons  are  made  with  reference  to  some  specific 
character  or  attribute,  this  comparison  may  take  either 
of  two  forms.  We  may  place  in  one  group  all  the 
instances  in  which  the  character  appears  and  then 


128  AN  OUTLINE  OF  LOGIC 

try  to  ascertain  what  other  character  is  paired  off 
with  it.  This  occurs,  for  example,  if  we  try  to  deter- 
mine whether  coffee  is  the  cause  of  sleeplessness.  Or, 
secondly,  we  may  take  an  average  of  a  given  group 
and  compare  it  with  some  other  average,  as  when 
the  average  wages  of  a  certain  period  are  compared 
with  the  average  wages  of  some  other  period,  in  order 
to  determine  the  influence  of  a  protective  tariff  or 
of  the  introduction  of  labor-saving  machinery.  The 
average  may  not  fit  any  one  case  precisely,  but  may 
nevertheless  serve  to  point  out  a  causal  connection. 
Similarly,  the  character  that  is  found  to  be  causally 
connected  with  the  first  character  may  qualify  the 
group  as  a  whole — e.g.,  a  low  death  rate — but  not 
the  individual  members. 

The  Method  of  Difference. — We  are  now  ready 
to  state  the  method  by  which  causal  connections  are  de- 
termined. After  the  group  has  been  formed  with  refer- 
ence to  a  given  character,  we  seek  for  the  concomitant 
of  this  character.  The  comparison  of  the  groups 
shows  that  these  two  characters  vary  together,  being 
present  in  the  one  group  and  absent  from  the  other. 
Thus  vaccination  and  low  death-rate  (or  low  rate  of 
attack)  mark  the  one  group  as  compared  with  the 
other.  The  groups  are  alike  in  many  respects,  but 
it  is  the  difference  between  the  groups,  and  not  the 
resemblance,  that  counts;  and  so  the  method  which 
underlies  the  procedure  has  been  called  the  Method 
of  Difference.  It  has  been  stated  by  Mill  as  fol- 
lows: "If  an  instance  [or  group  of  instances]  in 
which  the  phenomenon  under  investigation  occurs, 
and  an  instance  [or  group  of  instances]  in  ivhich  it 
does  not  occur,  have  every  circumstance  in  common 


THE  PROOF  OF  CAUSAL  CONNECTIONS   129 

save  one,  that  one  occurring  only  in  the  former;  the 
circumstance  in  which  alone  the  two  instances  [or 
groups  of  instances]  differ  is  the  effect  or  the  cause 
.  .  .  of  the  phenomenon."  *  This  statement,  it  may 
be  noticed,  is  so  worded  as  to  include  the  applica- 
tion of  the  method  not  only  to  groups  but  also  to 
single  instances;  an  application  which  will  be  con- 
sidered later.  The  method  has  been  stated  more 
concisely  in  this  way:  "  Whatever  alone  is  present 
in  a  case  when  the  phenomenon  to  be  investigated 
occurs,  and  absent  in  another,  when  that  phenomenon 
does  not  occur,  other  circumstances  remaining  the 
same,  is  causally  connected  with  that  phenomenon."  f 
According  to  this  method  only  one  circumstance 
must  be  found  to  vary  with  the  phenomenon  under 
consideration.  If  more  than  one  circumstance 
varies,  the  conclusion  is  not  valid. $  If  we  com- 
pare this  method  with  the  method  discussed  in 
the  preceding  chapter  we  find  that  the  Method  of 
Difference  varies  only  one  circumstance,  whereas  the 
Method  of  Agreement  attempts  to  vary  all  the  cir- 
cumstances except  one. 

In  principle  the  Method  of  Difference  is  very  simple, 
but  in  practice  the  application  may  be  very  difficult. 
Certain  fallacies  occur  with  sufficient  frequency  to 
merit  special  attention.    These  are : 

I.  Plurality  of  Points  of  Difference. — The  first 
source  of  error  consists  in  varying  more  than  one 
point  of  difference.  If  the  comparison  of  the  two 
groups  shows  that  one  of  the  groups  has  the  char- 

*Mill,  System  of  Lcgic,  Book  III.,  Chapter  VIII.,  §2. 
f  Creighton,  An  Introductory  Logic,  p.  205. 
%  For  an  illustration,  cf.  Forum,  Vol.  26,  p.   354,  Article, 
"Does  College  Education  Pay?" 


130  AN  OUTLINE  OF  LOGIC 

acters  A  and  B,  while  the  other  is  like  the  first, 
except  in  the  fact  that  it  has  neither  A  nor  B,  we 
assume  a  causal  connection  between  A  and  B.  It 
may  happen,  however,  that,  besides  A  and  B,  there 
is  present  a  third  character  C,  which  we  have  over- 
looked. The  one  group,  then,  has  A,  B,  and  C,  while 
the  other  group  has  none  of  the  three.  In  this  case 
we  may  be  unable  to  infer  to  a  causal  connection 
between  A  and  B,  since  the  connection  may  lie  between 
B  and  C,  leaving  A  causally  independent  of  the 
two. 

As  an  exemplification  of  this,  we  may  cite  an  in- 
ference that  was  supposed  to  be  warranted  by  the 
experience  of  one  of  our  larger  cities,  which  had 
voted  to  increase  materially  the  price  of  liquor  licenses. 
The  police  records,  for  the  period  immediately  sub- 
sequent to  the  time  when  the  new  law  went  into 
effect,  showed  a  distinct  decrease  in  the  amount  of 
crime.  By  the  method  of  difference  we  should  nat- 
urally attribute  this  fact  to  the  high  license.  But  it 
was  found  that  after  the  election  the  officials  who 
issued  the  licenses  had  been  much  more  careful  than 
before  to  issue  licenses  only  to  applicants  of  good 
moral  character.  This  fact  alone  might  account  for 
the  decrease  in  crime,  leaving  the  higher  license  with- 
out effect  upon  the  result. 

How  easily  group  comparisons  may  suggest  falla- 
cious inferences  appears  from  the  following:  "  Con- 
trary to  the  popular  idea  there  are  not  so  many 
wealthy  Jews  in  proportion  to  the  population  as  there 
are  non-Jews.  It  is  said  that  there  are  four  thousand 
millionaires  in  New  York  [City],  and  as  the  Jews 
form  20  per  cent,  of  the  population,  there  should  be 


THE  PROOF  OF  CAUSAL  CONNECTIONS   131 

eight  hundred  Jewish  millionaires.  The  fact  is  that 
there  are  not  two  hundred,  and  even  these  are  only 
moderately  millionaires. ' '  While  the  article  *  in  which 
this  passage  occurs  makes  no  further  comment  upon 
this  difference  between  the  Jewish  and  the  Gentile 
population,  one  might  be  tempted  to  take  it  as  an 
indication  that  the  Jews  are  an  inferior  class  in  the 
commercial  world.  There  are,  however,  important 
points  of  difference  to  be  considered.  In  the  first 
place,  New  York,  being  a  large  commercial  center, 
is  a  point  towards  which  the  millionaires  of  the  entire 
country  naturally  gravitate.  Hence  the  number  of 
millionaires  in  New  York  city  is  determined  in  part 
by  the  size  of  the  population  from  which  it  can  draw 
its  millionaires.  Now  the  article  just  mentioned  in- 
forms us  that ' '  The  Jews  in  the  United  States  number 
not  more  than  a  million  and  a  half.  As  New  York 
is  the  chief  port  of  entry  of  the  country,  and  at  the 
same  time  the  metropolis,  fully  one-half  of  all  these 
Jews  are  living  permanently  in  New  York. ' '  In  other 
words,  New  York  city  contains  about  5  per  cent,  of 
the  Gentile  population  of  the  United  States,  whereas 
it  contains  50  per  cent,  of  the  Jewish  population. 
Hence  the  Jewish  population  outside  of  New  York 
city  can  contribute  relatively  fewer  millionaires  than 
can  the  Gentiles. 

A  further  point  of  difference  is  implied  in  a  passage 
which  speaks  of  "  the  tremendous  influx  of  hundreds 
of  thousands  of  more  or  less  friendless  and  helpless 
Russian  and  Roumanian  Jews  within  the  last  twenty 
years. ' '    Owing  to  this  great  influx  it  would  obviously 

*  New  York  Independent,  Nov.  30,  1905,  Article,  "  The  Jew 
of  To-day"    (p.   1272). 


132  AN  OUTLINE  OF  LOGIC 

be  unfair  to  draw  inferences  as  to  commercial  ability 
from  a  comparison  of  the  Jews  with  the  rest  of  the 
population,  since  the  latter,  taken  as  a  whole,  has 
had  a  better  opportunity  to  acquire  wealth. 

II.  Plurality  of  Causes. — The  second  of  these  fal- 
lacies is  really  a  special  form  of  the  first.  We  may,  for 
example,  attribute  our  sleeplessness  to  coffee,  on  the 
ground  that  if  we  put  together  those  occasions  when 
we  drank  coffee  the  sleeplessness  was  present,  while 
on  the  other  occasions  it  was  not.  Or  it  may  be 
argued  that  it  is  a  good  practice  to  restore  convicts 
to  freedom  on  parole,  the  reason  given  being  that 
of  the  criminals  thus  treated  a  low  percentage  revert 
to  crime  as  compared  with  those  who  are  compelled 
to  serve  out  their  sentence  and  are  then  released  with- 
out condition.  This  may  seem  conclusive,  and  yet 
the  parole  system  might  have  nothing  to  do  with 
the  reform  of  the  prisoners,  and  the  coffee  might  have 
nothing  to  do  with  the  sleeplessness.  It  may  be  that 
of  the  convicts  upon  whose  records  we  base  the  con- 
clusion one  was  kept  from  temptation  by  a  friend, 
a  second  largely  through  absence  of  opportunity,  while 
a  third  was  reformed  through  religious  influences,  and 
so  on.  Instead  of  one  cause  there  may  be  a  set  of 
causes,  all  tending  towards  the  same  result.  The 
character  or  circumstance  that  they  have  in  common 
may  have  no  connection  whatever  with  this  result. 

This  error,  however,  is  likely  to  occur  only  if  the 
group  in  question  contains  but  few  members.  Where 
but  few  cases  are  concerned,  the  conjunction  of  the 
two  characters  which  are  common  to  the  group  and 
which  are  erroneously  supposed  to  be  causally  con- 
nected, may  be  a  mere  coincidence.    We  must  allow 


THE  PROOF  OF  CAUSAL  CONNECTIONS   133 

for  the  possibility  that  the  convicts  who  were  un- 
usually fortunate  after  being  released  from  the  peni- 
tentiary merely  happened  to  be  the  same  as  those 
who  were  released  on  parole.  Similarly,  a  teacher 
may  assume  that  the  disturbance  which  occurs  shortly 
after  a  certain  boy  entered  the  room  merely  happens 
to  occur  at  that  time.  But  if  this  happens  time  after 
time — i.e.,  if  the  group  of  occurrences  becomes  large 
— it  finally  becomes  impossible  to  ascribe  the  con- 
junction to  coincidence. 

It  may  be  said  that  this  error  could  not  occur  if 
we  had  really  conformed  to  the  requirements  of  the 
method,  since  it  is  stated  that  the  conclusion  follows 
only  on  condition  that  '  other  circumstances  remain 
the  same.'  This  objection  is  undoubtedly  correct. 
The  plurality  of  causes  is  an  error  that  can  arise  only 
under  an  imperfect  application  of  the  method.  It 
may  be  replied,  however,  that  this  imperfection  of 
application  is  not  merely  accidental.  The  Method  of 
Difference,  like  the  Method  of  Agreement,  involves 
an  ideal  of  proof  that  can  never  be  fully  attained 
in  practice.  Since  every  individual  member  of  a  class 
has  something  about  him  which  is  unique  and  which 
is  therefore  not  found  in  the  other  class,  it  is  im- 
possible to  have  all  the  circumstances  the  same.  More- 
over, it  is  never  possible  to  have  a  complete  knowledge 
of  all  these  other  circumstances.  As  the  method  is 
actually  employed,  this  proviso  as  to  '  other  circum- 
stances '  is  taken  to  mean,  '  all  other  circumstances 
remaining  the  same,  in  so  far  as  they  might  be  sup- 
posed to  be  relevant  to  the  situation.'  Here  again 
we  must  substitute  for  complete  proof  an  appeal  to 
the  principle  that  all  doubt  must  be  motivated.    When 


134  AN  OUTLINE  OF  LOGIC 

we  fall  into  the  error  called  plurality  of  causes, 
we  vary  more  than  one  circumstance,  and  this  circum- 
stance is  a  different  one  for  each  of  the  cases. 

III.  Merely  Apparent  Point  of  Difference. — A 
third  error  that  is  sometimes  committed  in  connection 
with  this  method  consists  in  comparing  groups  which 
appear  to  differ  in  a  certain  respect  when  in  reality 
they  do  not.  This  fallacy  is  the  opposite  of  the  fore- 
going. Instead  of  comparing  groups  which  differ  in 
more  than  one  important  respect,  we  compare  groups 
with  respect  to  a  merely  apparent  point  of  difference. 
Some  time  ago,  for  example,  the  United  States  census 
reports  indicated  a  rate  of  increase  among  negroes 
that  was  much  greater  than  that  among  whites.  This 
indication  attracted  much  attention  and  caused  some 
alarm.  It  was  found  afterwards,  however,  that  the 
difference  in  the  groups  was  due  to  the  manner  in 
which  the  figures  were  taken.  The  earlier  censuses 
had  been  taken  rather  carelessly,  so  far  as  the  negro 
population  was  concerned.  The  later  figures  were 
the  outcome  of  greater  effort  and  care,  with  the  result 
that  many  colored  people  were  included  who  had  not 
been  counted  on  the  previous  occasions. 

In  a  similar  way  later  censuses  have  shown  a  de- 
cided increase  in  the  number  of  infirmities,  such  as 
blindness,  deafness,  mental  feebleness,  etc.  These  in- 
firmities were  apparently  growing  faster  proportion- 
ately than  the  total  population.  This  is  now  explained 
by  the  fact  that  the  figures  for  such  infirmities  are 
more  easily  obtained  than  formerly,  because  it  is  now 
more  customary  to  have  such  cases  cared  for  in  hos- 
pitals and  special  institutions.* 

*  Forum,  Vol.  31,  p.  683,  Article,  "Statistical  Blunders." 


THE  PROOF  OF  CAUSAL  CONNECTIONS   135 

The  following  newspaper  editorial,  entitled,  '  Is 
Crime  really  Increasing?  '  illustrates  both  the  neces- 
sity of  having  a  sufficient  number  of  instances  before 
we  can  infer  a  causal  connection  and  the  fallacy  of 
drawing  an  inference  from  a  merely  apparent  point  of 
difference : 

"  The  police  report  of  the  city  of  Washington  once 
contained  the  statement  that  during  the  previous  year 
300  per  cent,  of  the  Turks  resident  in  our  national 
capital  had  been  arrested.  Further  investigation  re- 
vealed the  fact  that  the  number  of  Turks  resident  in 
our  national  capital  was  one.  This  Turkish  popula- 
tion of  one  had  been  arrested  three  times.   .    .    . 

"  A  few  months  ago  in  Chicago  there  was  a  great 
deal  of  talk  about  the  '  increase  in  crime.'  Several 
holdups  had  occurred  almost  simultaneously.  It  is 
difficult  to  persuade  holdups  to  follow  each  other  with 
due  regard  for  precedence.  They  simply  will  not  main- 
tain the  decent  intervals  which  the  procession  of 
averages  requires.  They  come  in  bunches.  The  con- 
sequence of  the  bunch  which  arrived  in  Chicago  at 
the  time  in  question  was  that  police  officers  were  inter- 
viewed, sermons  were  preached,  and  an  anti-crime 
committee  was  organized.  The  newspaper  men  who 
worked  on  crime  at  that  time  will  remember  that 
the  actual  proofs  of  an  increase  in  crime  were  most 
humiliatingly  difficult  to  discover.  Chicago  has  no 
body  of  statistics  covering  either  enough  ground  or 
enough  time  to  make  generalizations  possible. 

"  The  number  of  arrests  means  very  little.  It  may 
be  the  result  of  exceptional  laxity  or  of  exceptional 
severity  on  the  part  of  the  police.  And  thousands  of 
persons  who  have  been  arrested  are  released  without 


136  AN  OUTLINE  OF  LOGIC 

records  sufficient  to  establish  either  their  guilt  or 
innocence."  * 

Inference  to  Other  Cases. — It  was  stated  that  the 
proof  of  a  causal  connection  gives  us  only  an  abstract 
or  '  loose  '  generalization.  In  order,  therefore,  to 
extend  our  results  to  other  cases  we  must  be  sure 
that  these  are  in  all  essential  respects  like  the  one 
which  we  have  studied  and  which  has  yielded  evidence 
of  a  causal  connection.  Thus  we  may  ascertain  by 
the  Method  of  Difference  that  in  some  specific  case 
the  number  of  arrests  for  drunkenness  is  causally 
connected  with  the  amount  of  liquor  that  is  consumed 
in  that  particular  locality.  If,  therefore,  two  localities 
are  found  upon  comparison  to  differ  considerably  in 
the  number  of  arrests  for  drunkenness  in  proportion 
to  the  total  population,  the  inference  is  naturally 
drawn  that  in  the  one  with  the  greater  number  of 
arrests  drunkenness  is  a  more  common  occurrence  than 
in  the  other.  As  was  pointed  out,  however,  in  the 
discussion  of  relative  terms,  this  inference  assumes 
that  the  attitude  of  the  police  is  the  same  in  the 
two  places,  which  may  not  be  the  case.  There  may 
be  relatively  fewer  arrests  in  the  '  wide-open  '  town, 
just  because  the  police  takes  no  notice  of  any  but 
the  most  flagrant  cases.  The  inference  which  passes 
from  number  of  arrests  to  amount  of  drunkenness  as- 
sumes both  that  there  is  the  same  standard  for  what 
is  meant  by  drunkenness  and  that  there  is  the  same 
diligence  in  the  enforcement  of  the  law.  Unless  these 
assumptions  are  true,  the  inference  does  not  follow. 

In  a  college  debate,  some  years  ago,  on  the  restric- 

*Cf.  also  Forum,  Vol.  29,  p.  59G,  Article,  "Is  Crime  In- 
creasing? " 


THE  PROOF  OF  CAUSAL  CONNECTIONS   137 

tion  of  immigration  by  means  of  an  educational  test, 
the  side  favoring  such  a  test  lost  the  debate  because 
it  assumed  that  the  results  of  group  comparisons  could 
be  generalized  indefinitely.  Such  comparisons  in  coun- 
tries like  the  United  States,  England,  and  Germany 
show  a  connection  between  illiteracy  and  crime.  In 
these  countries  a  high  percentage  of  illiteracy  in  any 
given  group  signifies  a  high  percentage  of  crime.  It 
was  supposed  that  the  same  must  be  true  of  countries 
like  Hungary  and  Russia ;  which  is  not  necessarily  the 
case,  since  the  difference  in  educational  conditions  in 
these  latter  countries  makes  illiteracy  a  much  more 
uncertain  index  to  moral  character. 

The  Proof  of  Causation  as  Dependent  upon 
Number  of  Instances. — In  group  comparisons  the 
purpose  of  bringing  together  a  number  of  instances 
is  to  eliminate  irrelevant  circumstances.  The  circum- 
stance that  is  common  to  all  the  cases  is  causally  con- 
nected with  the  phenomenon,  provided  we  have  cases 
enough  to  guard  against  plurality  of  causes  and  to 
make  sure  that  there  is  no  other  common  circumstance 
which  might  account  for  the  facts. 

We  may  now  raise  the  question  how  many  in- 
stances are  necessary  in  order  to  achieve  this  result. 
It  has  already  appeared  that  we  cannot  rely  upon 
numbers  alone.  It  is  never  possible  to  comply  fully 
with  the  demands  of  the  Method  of  Difference.  So 
instead  of  varying  all  the  circumstances  but  one,  we 
fall  back  upon  the  principle  that  all  doubt  must  be 
motivated.  There  must  be  something  about  the  situa- 
tion that  gives  warrant  to  the  doubt.  The  result  is 
that  some  inferences  may  be  proved  by  fewer  in- 
stances than  others,  because  in  some  cases  a  justifiable 


138  AN  OUTLINE  OF  LOGIC 

doubt  is  easily  removed,  while  in  others  it  is  not. 
Or,  to  put  it  differently,  there  are  situations  in  which 
it  is  comparatively  easy  to  show  that  there  is  no  reason 
to  think  that  other  circumstances  have  not  remained 
the  same,  while  in  others  this  is  much  more  difficult. 

As  an  illustration  of  this  fact  we  may  compare  the 
proof  by  the  Method  of  Difference  that  pistol-shots 
produce  death  or  that  pin-pricks  produce  pain,  with 
the  proof  that  tariff  causes  prosperity  or  that  a  cer- 
tain drug  cures  an  ailment.  With  the  same  number 
of  instances  we  may  have  very  different  degrees  of 
proof.  The  prosperity  may  well  have  been  caused 
by  a  concomitant  change  in  industrial  or  agricultural 
conditions,  and  the  cure  may  be  due  to  the  faith  of 
the  patient  in  the  efficacy  of  the  remedy,  or  to  the 
processes  going  on  in  the  organism  independently  of 
the  drug. 

It  would  not  be  incorrect  to  ascribe  this  difference 
in  certainty  to  the  difference  in  the  time-interval  be- 
tween the  alleged  cause  and  the  alleged  effect.  A 
pistol-shot  inflicts  injury  on  the  spot,  whereas  the 
effects  of  a  tariff  appear  only  after  a  considerable 
lapse  of  time.  This  longer  interval  makes  it  possible 
for  numerous  other  changes  to  occur,  and  these 
changes  may  have  a  bearing  upon  prosperity.  The 
relation,  therefore,  between  tariff  and  prosperity  may 
be  nothing  more  than  a  coincidence.  Since  prosperity 
may  occur  without  any  tariff,  we  know  that  a  tariff 
is  not  an  indispensable  condition.  On  the  other  hand, 
to  suppose  that  the  effects  of  the  pistol-shot  are  due 
to  other  and  unknown  causes  would  be  clearly  un- 
motivated. 

This  time-interval,  however,  can  reasonably  disturb 


THE  PROOF  OF  CAUSAL  CONNECTIONS   139 

our  confidence  only  in  so  far  as  it  furnishes  other 
causes  an  opportunity  to  play  a  part  in  the  result. 
If  we  happen  to  know  enough  about  the  situation 
to  protect  ourselves  against  this  contingency,  we  may 
find  that  some  inferences,  in  which  a  comparatively 
long  interval  is  involved,  are  safer  than  others  in 
which  the  interval  is  shorter.  Thus  we  may  feel  more 
sure  that  sterilization  or  alcohol  prevents  decay  than 
that  a  certain  effect  is  due  to  a  drug  and  not  to  some 
other  cause.  In  other  words,  the  time-interval  is  sig- 
nificant only  in  so  far  as  we  are  unable  to  control 
the  conditions  of  the  result.  In  a  properly  conducted 
laboratory  experiment,  for  example,  there  can  be  no 
reasonable  doubt  about  the  conclusion,  even  if  con- 
siderable time  is  involved,  whereas  this  is  not  true  in 
the  case  of  experimental  legislation. 

It  appears,  then,  that  our  confidence  in  the  results 
obtained  by  the  Method  of  Difference  is  properly  deter- 
mined more  largely  by  our  knowledge  of  other  possible 
causes  than  by  the  mere  number  of  instances.  Unless 
we  bring  some  knowledge  to  the  situation,  the  method 
cannot  be  applied  at  all.  The  more  knowledge  we 
possess  the  less  we  are  dependent  upon  numbers.  A 
single  instance  is  just  as  valuable  as  a  great  number, 
if  we  can  make  sure  that  there  is  only  one  circum- 
stance which  varies  with  the  phenomenon.  We  have 
already  noticed  that  the  Method  of  Difference  may 
be  applied  to  single  cases  as  well  as  to  groups.  But 
if  a  single  instance  is  to  be  conclusive,  it  is  ordinarily 
necessary  that  we  introduce  the  cause  ourselves  and 
then  observe  that  the  effect  follows  at  once,  i.e.,  we 
must  resort  to  experiment.  If  experiment  is  im- 
possible, as,  e.g.,  in  the  study  of  the  relation  between 


140  AN  OUTLINE  OF  LOGIC 

the  prices  of  food  and  number  of  marriages,  or  if 
experiment  is  indecisive,  because  the  relation  of  cause 
and  effect  is  too  indirect  or  long-delayed,  as  in  vac- 
cination or  prohibitive  legislation,  we  must  rely  upon 
numbers  to  make  good  the  deficiency.  Situations  may 
occur,  therefore,  in  which  a  single  instance  is  sufficient 
to  prove  the  point.  This  is  more  particularly  true 
under  laboratory  conditions,  where  all  the  essential 
circumstances  are  under  our  control.  It  should  be 
added,  however,  that  such  situations  are,  after  all, 
rather  exceptional.  Even  in  the  best-regulated  labora- 
tory experiment  the  experimenter  is  pretty  sure  to 
verify  his  results  by  the  repetition  of  the  experiment, 
and  frequently  he  is  not  entirely  easy  until  he  learns 
that  his  co-workers  in  the  same  field  have  been  able 
to  get  the  same  results.  Ordinarily  we  all  insist  upon 
repetition  in  the  case  of  new  causal  relations,  and 
the  more  strange  they  are  the  more  we  feel  the  need  of 
corroborating  evidence.  In  general  we  may  say  that 
the  number  of  cases  necessary  to  prove  a  causal  con- 
nection varies  in  inverse  ratio  to  our  knowledge  of  the 
conditions. 

This  need  of  further  proof,  i.e.,  of  more  instances, 
is  due,  of  course,  to  the  fact  that  we  are  not  sure 
whether  the  two  cases  compared  possess  only  a  single 
point  of  difference.  The  elimination  of  other  possible 
points  of  difference  must  be  done  through  the  medium 
of  numbers,  if  we  do  not  feel  sufficiently  sure  of  the 
single  experiment.  An  experiment  is  nothing  but  an 
observation  that  occurs  under  unusually  favorable 
conditions,  viz.,  conditions  that  are  under  our  own 
control.  This  control,  however,  is  a  matter  of  degree, 
and  for  this  reason  we  may  find  it  necessary  to  pro- 


THE  PROOF  OF  CAUSAL  CONNECTIONS   141 

tect  ourselves  against  the  operation  of  circumstances 
which  have  escaped  our  notice,  i.e.,  to  make  sure  that 
the  two  cases  possess  only  a  single  point  of  difference. 
There  is  a  constant  tendency  to  overlook  as  irrelevant 
all  circumstances  except  those  in  which  we  are  directly 
interested,  and  thus  to  incur  the  risk  of  varying  more 
than  one  factor.  This  is  well  shown  in  the  following 
quotation:  "  When  Pasteur  was  investigating  the 
causes  of  splenic  fever,  he  adopted  very  early  in 
the  inquiry  the  theory  of  Dr.  Davaine,  that  the  dis- 
ease was  due  to  the  presence  of  a  certain  parasite 
in  the  blood,  and  that  consequently  the  same  disease, 
showing  the  presence  of  the  same  parasite,  could  be 
communicated  to  other  animals  by  inoculation.  On 
the  other  side,  two  professors,  to  whom  the  theory 
did  not  commend  itself,  brought  forward,  as  a  trium- 
phant refutation  of  it,  what  seemed  at  first  a  plainly 
contradictory  fact.  They  had  inoculated  some  rabbits 
with  the  blood  of  an  animal  which  had  died  of  splenic 
fever,  and  though  the  rabbits  had  died  very  rapidly, 
no  trace  of  the  expected  parasite  had  been  found  in 
them,  either  before  or  after  their  death.  Moreover, 
their  blood  again  had  been  used  to  inoculate  other 
rabbits,  and  these  too  had  died  in  the  same  rapid 
manner,  but  with  the  same  disregard  of  what  the 
theory  further  required.  Davaine  at  once  disputed 
the  fact.  That  is  to  say,  he  insisted  that  the  two  pro- 
fessors must  have  used  blood  which  was  not  properly 
infected  with  splenic  fever,  but  with  some  other  dis- 
ease. The  professors,  however,  were  equally  certain 
of  their  facts ;  they  had  got  their  materials  from  the 
best  available  source,  namely,  from  the  director  of 
an  establishment  where  numerous  animals  which  had 


142  AN  OUTLINE  OF  LOGIC 

died  of  splenic  fever  were  constantly  brought.  But 
in  order  to  convince  the  stubborn  theorist  they  tried 
the  experiment  again,  this  time  obtaining  their  ma- 
terials from  the  most  experienced  veterinary  surgeon 
in  the  neighborhood.  Exactly  the  same  result  fol- 
lowed, and  the  facts  certainly  here  appeared  to  be 
too  strong  for  the  theory. 

"  It  was  some  years  later  when  the  real  weakness 
of  the  facts  themselves  came  to  light.  Davaine's 
theory  had  meanwhile  been  enlarged  and  improved 
by  the  discovery  that,  if  the  blood  used  for  inoculation 
has  already  begun  to  putrify,  the  animals  inoculated 
will  die  by  a  form  of  blood-poisoning,  quicker  in  its 
operation  than  splenic  fever,  and  too  quick  to  allow 
the  true  splenic  fever  parasite  time  to  multiply.  This 
suggested  a  new  inquiry  into  the  professors'  experi- 
ments, and  it  was  found  that  the  blood  used  by  them, 
although  certainly  taken  from  cases  of  splenic  fever, 
had  not  been  sufficiently  fresh.  So  that  the  fact  on 
which  they  had  relied  as  contradicting  the  theory 
turned  out  to  be  wrongly — i.e.,  incompletely — de- 
scribed. Through  merely  overlooking  the  detail  that 
the  animals  whose  blood  they  used  had  been  dead  some 
twenty-four  hours,  their  description  of  it  as  '  splenic 
fever  blood  '  became  essentially  false. ' '  * 

When  dealing  with  single  instances  we  incur  the 
same  danger  as  in  group  comparisons,  viz.,  the  danger 
of  extending  our  inference  to  cases  which  appear  to 
be  essentially  the  same  but  which  differ  in  important 
respects.  It  was  by  an  oversight  of  this  kind  that 
the  spontaneous  generation  of  life  was  once  supposed 
to  have  been  proved.  With  regard  to  the  evidence 
*  Sidgwick,    Process   of   Argument,    pp.    95-97. 


THE  PROOF  OF  CAUSAL  CONNECTIONS   143 

upon  which  this  conclusion  rests,  a  critic  says:  "  The 
proof  of  Bacterial  death  at  140°  Fahr.  consists  solely 
in  the  observed  fact,  that  when  a  certain  liquid  is 
heated  to  that  temperature  no  life  appears  in  it  after- 
wards; while  in  another  liquid  life  appears  two  days 
after  it  has  been  heated  to  212°.  Instead  of  con- 
cluding that  in  the  one  liquid  life  is  destroyed  and 
in  the  other  not,  it  is  assumed  that  140°  Fahr.  is  the 
temperature  for  both;  and  this  being  so,  the  life 
observed  in  the  second  liquid  is  regarded  as  a  case 
of  spontaneous  generation."*  The  original  experi- 
ment was  supposed  to  prove  a  causal  relation  between 
the  origin  of  life  and  conditions  which  did  not  in- 
volve the  presence  of  living  organisms.  The  experi- 
ment was  inconclusive,  because  it  was  based  upon 
a  false  generalization  involving  the  assumption  that 
living  organisms  had  been  eliminated  from  the  sub- 
stances used  in  the  experiment. 

Concomitant  Variations. — The  Method  of  Con- 
comitant Variations,  as  it  is  sometimes  called,  is  not 
a  radically  new  method,  but  merely  a  special  applica- 
tion of  the  Method  of  Difference.  By  the  Method  of 
Difference  we  can  establish  causal  relations,  on  the 
basis  of  the  fact  that  the  qualities  or  attributes  so 
related  are  found  to  be  present  and  absent  together. 
Now  it  sometimes  happens  that  the  variations  are 
of  a  quantitative  character.  If  when  one  of  the  two 
attributes  varies  in  the  way  of  less  and  more,  the 
other  attribute  is  found  to  undergo  variations,  we 
infer  that  they  are  causally  connected,  and  the  proof 
is  said  to  be  based  upon  the  Method  of  Concomitant 
Variations. 

*  Quoted  by  S'idgwick,  Fallacies,  p.  280. 


144  AN  OUTLINE  OF  LOGIC 

The  following  formulation  is  the  one  offered  by 
Mill  as  a  definition  of  this  method:  "  Whatever  phe- 
nomenon varies  in  any  manner  whenever  another 
phenomenon  varies  in  a  particular  manner,  is  either 
a  cause  or  an  effect  of  that  phenomenon,  or  is  con- 
nected with  it  through  some  fact  of  causation.'' " * 
The  application  of  the  method  is  excellently  illus- 
trated in  the  following  quotation:  "  The  illustra- 
tions of  this  law  are  infinitely  numerous.  Thus  Mr. 
Joule,  of  Manchester,  conclusively  proved  that  friction 
is  a  cause  of  heat  by  expending  exact  quantities  of 
force  by  rubbing  one  substance  against  another,  and 
showed  that  the  heat  produced  was  exactly  greater 
or  less  in  proportion  as  the  force  was  greater  or  less. 
We  can  apply  the  method  to  many  cases  which  had 
previously  been  treated  by  the  simple  method  of 
difference;  thus  instead  of  striking  a  bell  in  a  com- 
plete vacuum,  we  can  strike  it  with  a  very  little  air 
in  the  receiver  of  the  air-pump,  and  we  then  hear 
a  very  faint  sound  which  increases  or  decreases 
every  time  we  increase  or  diminish  the  density  of 
the  air.  This  experiment  conclusively  satisfies  any 
person  that  air  is  the  cause  of  the  transmission  of 
sound. 

"It  is  this  method  which  often  enables  us  to 
detect  the  material  connection  which  exists  between 
two  bodies.  For  a  long  time  it  had  been  doubtful 
whether  the  red  flames  seen  in  total  eclipses  of  the 
sun  belonged  to  the  sun  or  moon ;  but  during  the  last 
eclipse  of  the  sun,  it  was  noticed  that  the  flames 
moved  with  the  sun,  and  were  gradually  covered  and 
uncovered  by  the  moon  at  successive  instants  of  the 
•Mill,  System  of  Logic,  Book  III.,  Chapter  VIII.,  §6. 


THE  PROOF  OF  CAUSAL  CONNECTIONS   145 

eclipse.     No  one  could  doubt  thenceforth  that  they 
belonged  to  the  sun. 

' '  Whenever,  again,  phenomena  go  through  Periodic 
Changes,  alternately  increasing  and  decreasing,  we 
should  seek  for  other  phenomena  which  go  through 
changes  in  exactly  the  same  periods,  and  there  will 
probably  be  a  connection  of  cause  and  effect.  It  is 
thus  that  the  tides  are  proved  to  be  due  to  the  attrac- 
tion of  the  moon  and  the  sun,  because  the  periods 
of  high  and  low,  spring  and  neap  tides,  succeed  each 
other  in  intervals  corresponding  to  the  apparent  revo- 
lutions of  those  bodies  round  the  earth.  The  fact 
that  the  moon  revolves  upon  its  own  axis  in  exactly 
the  same  period  that  it  revolves  round  the  earth, 
so  that  for  unknown  ages  past  the  same  side 
of  the  moon  has  always  been  turned  toward  the 
earth,  is  a  most  perfect  case  of  concomitant 
variations,  conclusively  proving  that  the  earth's 
attraction  governs  the  motions  of  the  moon  on  its 
own  axis. 

"  The  most  extraordinary  case  of  variations,  how- 
ever, consists  in  the  connection  which  has  of  late 
years  been  shown  to  exist  between  the  Aurora  Borealis, 
magnetic  storms,  and  the  spots  on  the  sun.  It  has 
only  in  the  last  thirty  or  forty  years  become  known 
that  the  magnetic  compass  is  subject  at  intervals  to 
very  slight,  but  curious  movements;  and  that,  at  the 
same  time,  there  are  usually  natural  currents  of  elec- 
tricity produced  in  telegraph  wires,  so  as  to  interfere 
with  the  transmission  of  messages.  These  disturb- 
ances are  known  as  magnetic  storms,  and  are  often 
observed  to  occur  when  a  fine  display  of  the  Northern 
or  Southern  Lights  is  taking  place  in  some  parts  of 


146  AN  OUTLINE  OF  LOGIC 

the  earth.  Observations  during  many  years  have 
shown  that  these  storms  come  to  their  worst  at  the 
end  of  every  eleven  years.  .  .  .  Close  observations 
of  the  sun  during  thirty  or  forty  years  have  shown 
that  the  size  and  number  of  the  dark  spots,  which  are 
gigantic  storms  going  on  upon  the  sun's  surface, 
increase  and  decrease  exactly  at  the  same  periods  of 
time  as  the  magnetic  storms  upon  the  earth's  surface. 
No  one  can  doubt,  then,  that  these  strange  phenomena 
are  connected  together,  though  the  mode  of  the  con- 
nection is  quite  unknown. ' '  * 

It  should  be  remembered  that  this  method  involves 
no  new  principle.  "While  usually  called  the  Method  of 
Concomitant  Variations,  it  is  merely  the  Method  of 
Difference  as  applied  when  the  variations  are  quanti- 
tative in  character.  Here  again  the  inference  to  a 
causal  connection  is  justified  only  if  there  is  reason 
to  think  that  no  relevant  circumstance  has  been  over- 
looked. The  Method  of  Concomitant  Variations  is  ap- 
plicable to  the  comparison  of  groups  as  well  as  to 
the  different  states  of  a  single  case  of  phenomenon. 
We  may  find,  for  example,  that  there  is  a  certain 
quantitative  relation  between  the  failure  of  crops  and 
the  number  of  crimes,  or  between  illiteracy  and  pau- 
perism. Of  course,  the  correlations  in  such  cases  is 
not  apt  to  be  very  precise  in  its  quantitative  aspects. 
Generally  speaking,  precision  is  possible  only  when 
we  approximate  laboratory  conditions  and  study 
single  instances.  In  the  laboratory,  as  well  as  in 
statistical  science,  the  Method  of  Concomitant  Varia- 
tions is  of  extreme  importance,  because  science  aims 

*  Jevons,  Lessons  in  Logic,  pp.  249-251;  quoted  by  Creigh- 
ton,  Logic,  pp.  212-213. 


THE  PROOF  OF  CAUSAL  CONNECTIONS   147 

at  quantitative  relations  wherever  these  can  be  ascer- 
tained. Success  in  this  direction  is  an  index  of  per- 
fection, and  so  it  is  not  surprising  that,  in  proportion 
as  a  science  develops,  it  tends  to  establish  more  and 
more  intimate  relations  with  mathematics. 


CHAPTER  XI 
PROBABILITY 

In  the  preceding  chapters  we  have  studied  the 
methods  by  which  universal  propositions  are  estab- 
lished and  causal  connections  ascertained.  A  universal 
proposition  concerns  an  entire  class,  since  it  asserts 
that  the  predicate  of  the  proposition  pertains  to  each 
member  of  the  class.  A  statement  of  causal  connec- 
tion is,  as  a  rule,  less  definite  on  the  side  of  extension 
or  denotation.  That  sunshine  causes  plants  to  grow 
is  not  universally  true,  but  only  if  certain  conditions 
of  soil,  moisture,  etc.,  are  realized.  In  other  words, 
a  proposition  which  affirms  a  causal  connection  im- 
plies a  proviso,  such  as,  '  under  ordinary  conditions,' 
or  '  other  things  equal.' 

The  number  of  strictly  universal  propositions  that 
can  be  made  is  relatively  small.  Nearly  all  rules  have 
exceptions,  and  statements  concerning  causation  rarely 
claim  universality.  It  is,  therefore,  a  problem  of 
some  importance  to  ascertain  how  we  can  make  asser- 
tions about  individual  facts.  In  so  far  as  the  in- 
dividual fact  comes  under  a  known  universal  rule 
there  is  no  occasion  for  difficulty.  If  smoke  is  an 
invariable  sign  of  fire,  it  is  easy,  in  any  particular 
case  of  smoke,  to  draw  the  appropriate  inference. 
But  if  the  rule  that  we  are  forced  to  employ  admits 
of  exceptions,  there  appears  to  be  no  guarantee  that 

148 


PROBABILITY  149 

the  case  before  us  is  not  one  of  the  exceptions,  and 
inference  becomes  hazardous.  Thus  banks  are  re- 
liable institutions,  as  a  rule,  but  this  is  small  comfort 
to  the  person  who  has  on  a  previous  occasion  reposed 
his  trust  and  his  money  in  the  institution  that  vio- 
lated the  rule.  What  he  now  wishes  to  know  is 
whether  this  particular  bank  is  trustworthy.  Stated 
more  generally,  the  question  is  how  we  are  to  proceed 
in  the  absence  of  reliable  universal  rules. 

It  is  evident  that  this  question  is  intimately  con- 
cerned with  our  everyday  conduct.  If,  for  example, 
an  individual  expects  to  live  another  year  or  another 
decade,  he  may  go  on  with  his  education,  contract 
obligations  extending  over  long  periods  of  time,  build 
a  house  according  to  his  private  notions  of  comfort, 
and  do  many  other  things  that  he  would  not  do  if 
he  entertained  the  prospect  of  an  early  dissolution. 
But  his  expectation  is  clearly  not  based  on  any  uni- 
versal rule,  since  many  persons  of  his  age,  station,  and 
condition  of  life  die  at  an  earlier  time  than  he  allows 
for  himself.  Upon  what  grounds  are  such  expecta- 
tions properly  based? 

Judgments  of  Probability  as  Based  upon 
Classes. — Since  inferences  based  upon  a  universal  con- 
nection cannot  be  obtained  in  the  situations  typified  by 
the  foregoing  illustration,  we  must  content  ourselves 
with  second  best.  Between  complete  assurance  and 
complete  ignorance  lies  the  domain  of  partial  assur- 
ance, ranging  all  the  way  from  one  extreme  to  the 
other.  One  way  in  which  this  partial  assurance,  which 
is  known  as  probability,  may  be  obtained,  is  by  a 
study,  not  of  the  individual  directly,  but  of  the  class  to 
which  he  belongs. 


150  AN  OUTLINE  OF  LOGIC 

By  a  study  of  the  class  many  questions  may  be 
tentatively  answered,  when  complete  knowledge  is 
lacking.  To  recur  to  our  illustration,  the  average 
individual  of  twenty-five  or  thirty  years,  if  he  is  of 
sound  health,  has  a  strong  expectation  that  he  will 
live  through  another  year,  although  he  does  not  even 
try  seriously  to  trace  out  the  conditions  involved. 
Instead  of  this,  he  is  apt  to  refer  to  the  fact  that 
the  death-rate  is  low  among  persons  of  his  age  and 
general  circumstances ;  in  other  words,  that  the  deaths 
constitute  comparatively  rare  exceptions  to  the  rule. 
Because  there  are  so  few  that  die,  his  chances  for 
survival  are  considered  very  good. 

This  type  of  reasoning  is  duplicated  in  many  other 
instances.  When  we  mail  a  letter  we  count  pretty 
confidently  upon  its  safe  arrival.  From  time  to  time- 
letters  get  lost,  through  carelessness,  in  railroad 
wrecks,  or  as  a  result  of  other  causes,  but  the  number 
of  those  which  get  lost  is  so  small  a  proportion  of 
the  total  number  that  we  treat  it  as  practically  a 
negligible  quantity.  For  the  same  reason  we  leave 
out  of  account  the  possibility  that  at  some  time  we 
shall  be  struck  by  lightning,  or,  when  we  make  a 
journey,  that  our  train  will  be  wrecked,  or  that  our 
home  will  be  destroyed  by  an  earthquake,  or  that  the 
stranger  of  whom  we  make  inquiries  as  to  directions 
will  be  insolent  or  show  annoyance.  If,  in  each  case, 
we  take  the  class  as  a  whole,  there  is  a  certain  per- 
centage of  results  one  way  and  a  certain  percentage 
the  other  way — e.g.,  a  certain  percentage  of  letters 
arrives  safely  while  a  certain  other  percentage  does 
not.  Of  course,  we  frequently  do  not  know  the  pro- 
portions with  any  such  accuracy  as  is  embodied  in 


PROBABILITY  151 

a  statement  of  percentages.  But  this  is,  in  a  sense, 
merely  incidental.  Our  inference  and  our  conduct 
are  determined  by  our  conception  of  these  propor- 
tions, in  that  we  consider  the  '  chances  '  greater  to 
the  degree  that  the  proportion  preponderates  in  a 
given  direction.  If  there  is  no  preponderance,  we 
say  that  the  '  chances  are  even.'  There  are  as  many 
cases  on  the  one  side  of  the  line  as  on  the  other.  The 
statistical  work  which  seeks  to  state  the  respective 
results  in  terms  of  percentages  merely  makes  our 
estimate  of  the  chances  more  definite  than  they  were 
before. 

The  Constancy  of  Classes. — If  we  are  to  deter- 
mine from  the  study  of  classes  the  probabilities  of 
their  individual  members,  there  must  be  a  certain 
constancy  in  the  behavior  of  the  class  as  a  whole. 
Within  certain  limits  this  requirement  is  met  re- 
markably well  by  the  facts.  "  The  total  number  of 
crimes  is  approximately  the  same  year  after  year; 
the  annual  death-rate,  the  apportionment  of  deaths, 
moreover,  to  the  several  diseases  as  their  evident 
causes,  the  number  of  missent  letters  that  reach  the 
Dead  Letter  Office  at  Washington  each  year,  the 
annual  number  of  suicides,  of  divorces,  all  these  di- 
verse events  indicate  a  regularity,  in  the  long  run,  as 
regards  their  numerical  estimate. "  *  As  another 
writer  says,  more  graphically:  "  With  astonishing 
precision  year  follows  year  in  the  assigned  causes  of 
fire  [in  New  York  City] .  '  Carelessness  with  matches  ' 
always  leads  by  the  inevitable  percentage,  and  so 
in  sequence:  '  Children  playing  with  fire,'  and  '  Cigar 
and  cigarette  ends  falling  through  gratings. '  So,  too, 
*  Hibben,  Logic,  p.  338. 


152  AN  OUTLINE  OF  LOGIC 

Jewish  Sabbath  lights,  and  Italian  tapers  carelessly 
burning  under  Saints  and  Madonnas,  kindle  their 
calculable  yearly  tale  of  horrors.  And,  by  some  iron 
decree,  the  average  annual  loss  for  each  fire  mounts 
unfailingly  to  $680,  and  varies  but  $1.50  in  two 
years.  And  then  there  is  that  persistent  daily  mean 
of  thirty  alarms.  As  you  watch  the  numbers  click 
to  their  calls,  you  may  think  to  see  the  hours  playing 
for  victims  a  ghastly  red-and-black  of  their  own — a 
roulette  of  demons. ' '  * 

It  is  on  the  basis  of  this  regularity  that  life  insur- 
ance companies  transact  their  business.  Owing  to  the 
constancy  of  classes  it  is  comparatively  easy  to  fix 
a  schedule  of  premiums  that  will  allow  a  safe  margin 
for  the  company.  It  should  be  noticed,  however,  that 
the  company  which  issues  the  policy  is  not  on  the 
same  footing  as  regards  probability  with  the  indi- 
vidual to  whom  the  policy  is  issued.  The  class  as  a 
whole  being  approximately  constant,  the  company 
knows  in  advance  just  about  what  to  expect.  "What 
the  company  does  not  know  is  which  of  the  members 
will  be  the  ones  to  die,  but,  from  the  standpoint  of 
the  company,  this  is  a  matter  of  indifference. 

The  reason  why  we  ever  seek  to  determine  proba- 
bility by  a  study  of  classes  is  that  the  causes  which 
decide  the  fate  of  the  individual  member  are  either 
too  complex  or  are  entirely  unknown  to  us.  The 
study  of  classes  is  a  sort  of  short  cut  to  the  result, 
a  more  or  less  artificial  simplification  of  a  problem 
too  complicated  for  us  to  handle  in  any  other  way. 
For  example,  let  us  suppose  that  some  one  should 

*  J.  F.  Carr,  "  Fighting  the  Fire,"  The  Outlook,  March  28, 
1908. 


PROBABILITY  153 

try  to  determine,  without  resort  to  statistics,  whether 
a  given  letter  will  arrive  at  its  destination.  In  order 
to  rule  out  the  chances  of  a  railway  wreck,  he  would 
have  to  consider  the  fitness  of  the  train  crew,  the  state 
of  the  roadbed,  the  condition  of  the  rolling  stock,  the 
danger  of  washouts,  and,  in  short,  the  entire  manage- 
ment of  the  road.  This  would  be  only  a  part  of 
the  work.  The  United  States  postal  service  would 
next  require  examination,  to  ascertain  whether  it 
could  be  intrusted  with  the  letter,  and  particularly 
the  mental  peculiarities  of  the  employes  whose  duty 
it  would  be  to  handle  this  letter.  A  study  of  this 
sort,  no  matter  how  far  it  was  carried,  would  be 
quite  as  likely  to  lead  to  bewilderment  as  to  any 
tangible  results,  if  there  were  no  statistics  to  guide 
our  expectations. 

The  Nature  of  Probability. —  It  may  seem  a  little 
peculiar  that  the  chances  or  probabilities  in  two  cases 
may  be  the  same,  while  the  outcome  is  very  different. 
Thus  the  chances  of  its  safe  arrival  may  be  as  great  for 
the  letter  that  is  lost  as  for  any  other.  This,  however, 
can  be  occasion  for  surprise  only  if  we  treat  '  chance,' 
which  is  properly  an  abstraction,  as  though  it  were 
a  concrete  agency  or  force,  struggling  for  the  attain- 
ment of  a  certain  end.  For  this  reason,  apparently, 
an  unusual  combination  of  circumstances  is  apt  to 
be  regarded  by  the  individual,  cheerfully  or  somberly, 
according  to  the  nature  of  the  case,  as,  '  just  his  luck,' 
and  as  something  more  potent  than  everyday  natural 
causation.  This  may  happen,  for  example,  if  a  com- 
bination of  circumstances  causes  him  to  miss  the 
steamer  which  is  lost  at  sea  on  that  selfsame  trip; 
or  if  a  storm  demolishes  his  house  without  injuring 


154  AN  OUTLINE  OF  LOGIC 

any  other  buildings.  It  is  well  known  that  gamblers 
as  a  class  are  much  disposed  to  regard  '  luck  '  in  this 
semi-superstitious  way. 

How  the  probabilities  may  be  the  same  in  different 
instances  without  a  corresponding  sameness  in  out- 
come ceases  to  be  a  mystery  if  we  bear  in  mind  that 
probability  is  not  the  name  of  an  agency,  nor  yet 
a  name  for  our  ignorance,  but  a  forecast  that  is  based 
upon  partial  knowledge.  If  our  knowledge  were  com- 
plete, the  term  '  chance  '  would  presumably  disappear 
from  our  vocabularies.  But  it  is  also  true  that  we 
cannot  speak  of  chance  unless  we  have  some  knowl- 
edge of  the  situation  in  question.  We  speak  of  chance 
or  probability  because  we  have  some  knowledge,  but 
not  as  much  as  is  necessary  for  certainty.  Proba- 
bility may,  therefore,  be  defined  as  the  degree  of 
expectation  that  is  warranted  by  the  premises. 

From  this  definition  it  is  evident  that  probability 
merely  tells  us  what  we  have  a  right  to  expect  in 
view  of  what  we  know.  If  we  know  nothing  further 
than  that  the  percentages  of  the  class  in  question  show 
a  preponderance  of  results  in  a  certain  direction,  we 
are  required  by  our  data  to  expect  that  the  result 
thus  indicated  will  occur  in  the  case  of  any  designated 
member,  the  proper  degree  of  expectation  being  deter- 
mined by  the  measure  of  preponderance.  When  we 
say  that  the  probabilities  of  safe  arrival  in  the  case 
of  different  letters  are  equal,  we  do  so  because  our 
information  is  limited  to  the  fact  that  they  both 
belong  to  the  same  class.  '  Probability  is  the 
guide  of  life  ';  and  if  we  act  upon  the  informa- 
tion that  we  have,  we  shall  be  right  oftener  than 
wrong. 


PROBABILITY  155 

How  Probability  is  Made  More  Accurate- 
Estimates  of  probability  that  are  based  on  our  knowl- 
edge of  classes  may  be  made  more  accurate  by  more 
painstaking  classifications.  The  exceptions  to  the  rule 
then  become  relatively  fewer.  If  we  happen  to  know 
nothing  about  a  man  except  that  he  is  thirty  years 
of  age,  the  probability  that  he  will  live  another  decade 
or  another  year  will  be  determined  by  the  mortality 
tables  for  the  entire  class  of  men  thirty  years  old. 
But  if  we  find  that  his  health  is  excellent,  we  are 
able  to  classify  him  with  a  smaller  group.  From  the 
group  of  persons  thirty  years  old  we  eliminate  all 
those  who  do  not  enjoy  good  health,  with  the  result 
that  the  death  rate  decreases  for  those  who  remain; 
and  if  he  is  engaged  in  a  healthful  occupation,  has 
good  habits,  and  comes  of  a  long-lived  stock,  the 
group  becomes  still  smaller,  with  a  constant  decrease 
of  the  death  rate.  Similarly  our  trust  in  a  bank  may 
be  increased  when  we  discover  that  it  is  not  only 
under  state  control,  but  under  the  management  of 
responsible  men  and  conservative  in  its  methods. 

The  Principle  Implied  in  Estimates  of  Prob- 
ability.—  The  principle  implied  in  judgments  of 
probability  is  that  if  a  particular  case  is  like  others 
in  certain  respects,  we  may  take  this  resemblance  as 
a  ground  for  expectation,  even  though  we  are  not 
acquainted  with  all  the  conditions  that  determine  the 
result.  We  spontaneously  generalize  from  the  pre- 
vious experiences  to  the  present  experience.  This 
is  not  only  justifiable  but  necessary,  because  we 
can  never  ascertain  the  totality  of  conditions  for 
any  event.  If,  therefore,  we  should  refuse  to  ac- 
cept   partial   knowledge,    and    to    act   upon    it,    life 


15G  AN  OUTLINE  OF  LOGIC 

would  be  impossible  and  knowledge  an  unattainable 
ideal. 

The  Function  of  Numbers  in  Estimates  of 
Probability. — The  function  of  numbers  is  twofold. 
In  the  first  place,  numbers  serve  to  make  our  estimates 
of  probability  more  definite.  Where  the  classes  are 
definitely  marked  off  by  easily  recognizable  likenesses 
and  are  sufficiently  large  in  extent,  as  in  the  case 
of  '  men, ' '  railroad  collisions, '  '  divorces, '  and  similar 
groups,  we  tend  to  estimate  the  probability  in  terms 
of  the  ratio  between  the  number  of  cases  in  which 
the  result  in  question  occurs  and  the  number  in  which 
it  does  not  occur.  The  basis  of  our  judgments  is 
indeed  resemblance.  We  infer  that  because  A  has 
been  attended  by  B  in  certain  other  cases,  therefore 
B  may  be  expected  in  the  present  case  of  A.  Other 
persons  who  have  made  a  journey  have  experienced 
the  disasters  of  collisions,  therefore  the  same  may 
be  expected  by  us,  if  we  undertake  to  travel  on  a 
train.  A  comparison  of  figures,  however,  shows  that 
the  degree  of  expectation  warranted  by  the  resem- 
blance is  in  this  case  very  slight.  The  preponderance 
of  probability  is  the  other  way.  Secondly,  a  judgment 
may  be  corrected  by  numbers  if  we  happen  to  infer 
from  the  wrong  resemblance.  Thirteen  at  table  is 
followed  by  a  death  within  a  year  in  a  certain  case 
or  cases,  therefore  the  same  may  be  expected  in  the 
present  case.  A  sufficiently  large  group  of  thirteen- 
at-table  cases,  however,  will  serve  to  show  that  the 
number  thirteen  has  no  particular  significance.  Num- 
bers of  instances,  therefore,  may  assist  the  judgment 
of  probability  in  that  they  enable  us,  wherever  nec- 
essary, to  make  sure  of  a  connection  between  circum- 


PROBABILITY  157 

stance  A  and  circumstance  B.  This  help,  however,  is 
merely  negative.  If  there  is  no  connection,  the  basis 
for  expectation  is  indeed  taken  away.  But  if,  on  the 
other  hand,  a  connection  is  discovered,  e.g.,  by  group 
comparisons,  we  are  not  yet  in  a  position  to  make  a 
judgment  of  probability.  This  can  be  done  only 
after  we  have  some  clue  as  to  the  ratio  between  the 
number  of  cases  in  which  the  given  result  occurs  and 
the  number  in  which  it  does  not  occur. 

Probability  as  Based  upon  Individual  Resem- 
blances.— We  have  seen  that  in  judgments  of  proba- 
bility the  ground  for  expectation  is  resemblance.  The 
cases  are  put  into  the  same  class,  because,  so  far 
as  we  know,  they  are  alike  in  all  important  respects. 
Then  when  a  new  case  presents  itself,  the  probability 
that  a  given  result  will  occur  may  be  stated  in  terms 
of  the  percentages  that  have  been  obtained  from  the 
study  of  the  class  as  a  whole. 

In  this  procedure  two  facts  should  be  noted.  The 
first  is  that  our  inference  is  based  upon  a  generaliza- 
tion. A  may  be  taken  as  a  sign  of  B ;  not  as  an 
unfailing  sign,  indeed,  but  as  a  reliable  sign  in  a  cer- 
tain percentage  of  cases.  The  second  is  that  the  infer- 
ence assumes  an  essential  likeness  between  the  new 
case  and  the  class  of  cases  from  which  the  estimate 
of  probability  is  derived. 

With  regard  to  this  essential  likeness,  however,  diffi- 
culties may  arise.  By  '  essential  likeness  '  is  meant 
complete  similarity,  so  far  as  the  purpose  of  the  argu- 
ment is  concerned.  Such  likeness  may  be  assumed,  if 
no  room  can  be  found  for  a  reasonable  doubt.  But 
we  may  have  reason  to  suspect  that  the  likeness  of  the 
present  case  to  other  cases  is  not  the  kind  of  likeness 


158  AN  OUTLINE  OF  LOGIC 

which  the  inference  requires.  In  order  to  make  the 
difficulty  concrete,  let  us  recur  once  more  to  the 
inference  that  a  given  letter  is  likely  to  arrive  safely 
at  its  destination.  "We  may  let  A  stand  for  '  letter/ 
and  B  for  '  safe  arrival.'  The  inference  from  A  to 
B  is  then  justified  if  the  letter  in  question  is  just 
an  ordinary  sort  of  letter,  with  no  peculiarity  about 
it,  so  far  as  we  know,  which  would  be  likely  to  make 
a  difference  in  the  result.  If,  however,  the  letter 
differs  widely  from  ordinary  letters  in  shape  or  size, 
or  if  the  address  is  written  very  illegibly,  or  if  the 
ink  is  of  a  kind  that  may  fade  in  a  very  short  time, 
we  have  a  different  problem  on  our  hands.  Or,  again, 
it  may  be  that  the  letter  contains  some  fragile  object, 
about  the  safety  of  which  we  are  in  doubt.  In  all 
such  situations  there  may  be  numerous  resemblances 
between  this  letter  and  other  letters,  and  yet  there 
may  be  ample  ground  for  doubt  whether  this  is  a 
'  letter  '  in  the  sense  which  warrants  an  inference 
to  '  safe  arrival. '  In  other  words,  if  the  circumstances 
are  widely  different  in  the  case  under  consideration, 
we  may  be  uncertain  whether  the  likeness  is  essential 
or  merely  accidental. 

While  it  may  be  true,  therefore,  that  A  is  a  sign 
of  B  '  as  a  rule,'  or  '  under  ordinary  conditions,' 
we  are  not  much  comforted  by  this  reflection,  if  we 
are  uncertain  whether  the  conditions  in  the  present 
instance  are  of  the  usual  kind.  It  is  plain  that  our 
knowledge  of  the  class  cannot  avail  us  much  in  dealing 
with  a  new  case,  so  long  as  the  reliability  of  the 
resemblance  is  in  doubt.  The  soundness  of  the  infer- 
ence then  necessarily  depends  upon  the  nature  of 
the  individual  resemblances  involved,  i.e.,  upon  the 


PROBABILITY  159 

resemblance  which  we  discover  on  this  particular 
occasion. 

The  reasoning  which  bases  itself  upon  this  kind  of 
resemblance  is  illustrated  in  the  argument  about  to 
be  quoted.  The  argument  is  directed  against  the 
proposition  defended  by  the  American  Colonies  that 
'  Taxation  without  Representation  is  Tyranny,'  and 
is  intended  to  show  that  a  colony  has  a  right  to  a 
voice  in  its  own  government  only  so  long  as  the 
supreme  authority  in  the  mother  country  sees  fit  to 
grant  this  right : 

"  An  English  colony  is  a  number  of  persons  to 
whom  the  king  grants  a  charter,  permitting  them  to 
settle  in  some  distant  country  and  enabling  them  to 
constitute  a  corporation,  enjoying  such  powers  as  the 
charter  grants,  to  be  administered  in  such  forms  as 
the  charter  prescribes.  As  a  corporation  they  make 
laws  for  themselves,  but  as  a  corporation  subsisting 
by  a  grant  from  higher  authority,  to  the  control  of 
that  authority  they  continue  subject.  .  .  .  The  char- 
ter, therefore,  by  which  provincial  governments  are 
constituted,  may  always  legally,  and  where  it  is  either 
inconvenient  in  its  nature  or  misapplied  in  its  use, 
may  be  equitably  repealed. ' '  * 

The  essential  point  of  this  argument  is  that  a  colony 
is  like  a  corporation.  The  latter  is  a  special  group 
of  persons  upon  whom  is  bestowed  a  special  right 
or  privilege.  The  same  is  true  of  the  colony.  In 
the  case  of  the  corporation  such  special  rights  are 
subject  to  the  pleasure  of  the  authority  by  which 
they  are  granted.  This  is  likewise  true,  therefore, 
of  the  colony.    But  if  this  be  the  case,  then,  according 

*  Johnson,  Taxation  no  Tyranny. 


160  AN  OUTLINE  OF  LOGIC 

to  the  argument,  a  colony  can  have  a  share  in  its  own 
government  only  so  long  as  the  authority  which 
granted  the  privilege  does  not  choose  to  withdraw  it. 
Colonies  cannot  claim  participation  in  their  own  gov- 
ernment as  a  right,  but  can  enjoy  it  only  as  a  special 
privilege. 

This  argument,  as  may  easily  be  shown,  rests  upon 
a  mistaken  resemblance.  It  is  doubtless  true  that 
both  corporations  and  colonies  may  have  special  rights 
bestowed  upon  them  and  that  these  special  rights 
may  be  terminated  by  the  higher  authority.  If,  how- 
ever, the  special  rights  of  a  corporation  be  taken  away, 
the  members  of  the  corporation  nevertheless  retain 
their  rights  as  private  citizens.  The  charter  refers 
to  special  rights,  not  to  the  rights  of  citizenship.  Now 
while  the  charter  of  a  colony  may  confer  special 
rights  upon  a  colony,  the  contention  of  the  colonists 
in  this  case  was  not  for  any  special  right,  but  for 
the  right  of  the  individual  colonists  to  citizenship. 
This  point  is  entirely  overlooked  in  the  argument. 
The  two  cases  compared  resemble  each  other  perhaps 
in  the  matter  of  special  rights,  and  the  generalization 
'  special  rights  may  be  taken  away,'  may  hold  for 
both.  In  the  matter  under  discussion,  however,  the 
cases  are  entirely  different,  and  the  argument  is,  there- 
fore, based  upon  a  false  resemblance. 

It  must  be  added  that  there  is  no  difference  in 
principle  if  we  compare  our  new  case,  not  with  a 
class  of  cases  in  which  the  generalization  holds  true, 
but  with  a  single  case.  Thus  it  may  be  argued  that 
since  Free  Trade  is  desirable  for  England,  it  is  desir- 
able for  America.  Here  again  a  generalization  under- 
lies the  inference,  viz.,  that  Free  Trade  is  desirable 


PROBABILITY  161 

or  conducive  to  welfare.  Assuming  that  a  connection 
has  been  established  between  '  Free  Trade  '  and  '  wel- 
fare,' this  connection  may  be  inferred  in  other  cases, 
if  the  conditions  are  essentially  the  same.  This  point 
has  already  been  discussed  on  a  previous  occasion 
(c/.  p.  136).  The  validity,  therefore,  of  the  inference 
depends  upon  the  question  whether  the  cases  com- 
pared are  alike  in  all  important  respects. 

It  has  been  shown  that  estimates  of  probability 
cannot  be  determined  by  what  we  know  about  a  class 
of  cases,  so  long  as  the  reliability  of  the  resemblance 
is  in  doubt.  Whenever  such  a  situation  arises,  we 
are  obliged  to  study  this  resemblance,  in  order  to 
ascertain,  if  possible,  whether  it  will  justify  the  infer- 
ence. An  argument  that  involves  a  resemblance  of 
the  kind  just  discussed,  viz.,  a  resemblance  which 
occurs  in  contexts  or  settings  so  different  from  each 
other  as  to  make  the  inference  seem  insecure,  is  called 
an  inference  from  analogy. 

The  Nature  of  Analogy. — Reasoning  from  analogy 
has  been  defined  as  follows:  "  Two  things  resemble 
each  other  in  one  or  more  respects ;  a  certain  proposi- 
tion is  true  of  one,  therefore  it  is  true  of  the  other. ' '  * 
This  definition,  however,  does  not  point  out  explicitly 
that  resemblance  is  a  wider  term  than  analogy.  As 
Mr.  Sidgwick  says,  "  Where  analogy  is  very  close, 
and  well  tested,  and  familiar,  as  between  cancer  and 
cancer,  or  man  and  man,  class-names  have  generally 
been  invented.  It  is  newly-seen  likeness,  doubtful 
likeness,  or  likeness  where  the  examples  are  rare,  that 
we  have  to  recognize  as  well  as  we  can  without  the 
aid  of  class-names.  And  it  is  to  these  kinds  of  like- 
*  Mill,  System  of  Logic,  Book  III.,  Chapter  XX.,  §  2. 


162  AN  OUTLINE  OF  LOGIC 

ness  especially  that,  as  a  rule,  we  give  the  name 
'  analogy. '  "  *  As  was  indicated  a  moment  ago,  an 
argument  that  is  based  upon  this  kind  of  likeness  is 
called  an  argument  from  analogy. 

Analogy  and  Classification. —  Analogy  expresses 
our  natural  tendency  to  assimilate  the  new  to  the 
old,  to  interpret  what  is  strange  and  unfamiliar  in 
the  light  of  what  we  already  know.  It  may,  there- 
fore, be  described  as  classification  in  the  making.  The 
resemblances  which  guide  us  are  called  analogies  so 
long  as  they  are  newly-seen,  rare,  or  doubtful;  but 
as  the  number  of  cases  increases,  analogy  passes  by 
insensible  stages  into  established  classification.  It  is 
accordingly  impossible  to  draw  a  hard  and  fast  line 
and  to  say  that  analogy  is  operative  on  one  side  of 
it  and  classification  on  the  other.  A  likeness  about 
which  we  were  in  doubt  at  the  outset,  because  not 
guaranteed  by  numbers,  may  become  well  attested  in 
the  end  and  acquire  a  class  name  of  its  own.  Whether 
our  inference  be  based  upon  an  analogy  or  upon  a 
familiar  classification,  the  connection  A — B  which 
supports  the  inference  is  the  same  in  kind,  but  in 
common  usage  it  is  ordinarily  not  until  a  class  has 
been  formed,  well-defined  or  ill-defined,  as  the  case 
may  be,  that  the  underlying  connection  is  called  a 
generalization. 

False  Analogy.— It  has  already  appeared  that  the 
danger  to  which  we  are  exposed  in  analogical  reason- 
ing is  the  danger  of  ignoring  differences  in  the  attend- 
ant circumstances.  This  is  exactly  the  same  danger 
as  the  one  which  we  encountered  in  the  study  of 
universal  connections.  In  reasoning  from  analogy, 
*The  Process   of  Argument,   p.   40. 


PROBABILITY  163 

however,  we  are  not  concerned  to  prove  a  universal 
connection,  but  to  show  that  a  given  generalization 
applies  to  the  case  in  hand ;  or,  to  state  it  differently, 
that  a  given  resemblance  justifies  the  inference  which 
we  make.  The  best  that  we  can  do  under  the  con- 
ditions is  to  scrutinize  the  new  context  in  which  the 
point  of  resemblance  A  is  found.  If  it  turns  out 
that  there  is  an  important  point  of  difference,  i.e., 
if  the  nature  of  the  resemblance  is  different  from 
what  it  was  supposed  to  be,  or  if  the  generalization  in- 
volves conditions  which  are  absent  in  the  new  case,  the 
argument  is  invalidated.  If  an  analogy  can  be  shown 
in  this  way  to  be  unreliable,  it  is  called  a  false  analogy. 
For  a  concrete  instance  of  false  analogy  we  may 
refer  to  the  argument,  just  discussed,  which  compares 
colonies  with  corporations.  As  a  second  illustration 
we  may  take  Carlyle's  analogical  argument  against 
the  representative  form  of  government.  According  to 
Carlyle,  this  kind  of  government  is  bound  to  fail, 
since,  as  he  puts  it,  a  ship  could  never  be  taken  around 
Cape  Horn  if  the  captain  were  obliged  to  consult 
the  crew  every  time  before  changing  his  course.  A 
generalization  is  implied,  something  like,  '  The  shar- 
ing of  power  involves  a  lack  of  efficiency.'  Granted 
that  this  holds  true  on  ships,  is  it  also  true  in  govern- 
ment? The  argument  asserts  that  the  two  cases  are 
alike,  but  it  offers  no  proof  that  the  difference  in 
circumstances  is  immaterial.  The  apparent  differ- 
ence, however,  is  so  great  that  caution  is  advisable. 
It  may  be  that  the  lack  of  efficiency  is  due  to  the 
sharing  of  power  under  certain  conditions  peculiar 
to  the  management  of  ships.  It  is  impossible  to 
prove  that  the  connection  between  '  sharing  of  power  ' 


164  AN  OUTLINE  OF  LOGIC 

and  '  lack  of  efficiency  '  is  universal,  for  the  cases 
are  not  of  such  a  kind  that  we  can  vary  all  the  other 
circumstances,  as  the  proof  of  a  universal  proposition 
requires. 

If  we  examine  Carlyle's  argument  more  closely,  we 
soon  find  that  it  rests  upon  a  false  analogy.  Certain 
important  differences  are  overlooked.  In  the  first 
place,  the  authority  shared  by  the  people  concerns 
the  legislative  rather  than  the  executive  branch  of 
government.  Hence  popular  government  leaves  the 
executive  a  free  hand  within  the  scope  of  the  laws, 
just  as  the  captain  has  a  free  hand  within  the  scope 
of  his  instructions.  And  secondly,  the  relation  of 
a  crew  to  a  ship  is  very  different  from  that  of  a  people 
to  their  government.  With  respect  to  this  relation, 
a  government  is  more  nearly  like  a  partnership,  in 
which  the  sharing  of  authority  is  not  necessarily  in- 
compatible with  efficiency. 

As  a  further  illustration  of  analogical  reasoning 
we  may  take  the  argument,  ascribed  to  the  Chinese, 
that  a  prince,  since  he  is  the  father  of  his  people, 
should  have  the  same  authority  over  his  subjects  that 
a  father  has  over  his  children.  The  generalization 
here  is  that  a  '  father  '  should  have  autocratic  power. 
This  right  is  generally  conceded  to  the  parent,  because 
affection  for  his  children  and  superior  wisdom  are 
presupposed.  If  these  conditions  are  absent,  the  ex- 
tension of  the  generalization  is  unwarranted.  With 
respect  to  these  conditions,  however,  the  two  cases  are 
widely  different,  and  so  the  analogy  has  no  value 
as  a  basis  for  this  inference. 

The  Value  of  Analogy. — The  correctness  of  ana- 
logical argument  depends,  as  we  have  seen,  upon  the 


PROBABILITY  165 

essential  similarity  of  all  the  relevant  circumstances. 
Whether  such  a  likeness  exists  can  be  determined  only 
by  an  analysis  of  the  new  context,  in  order  to  ascer- 
tain whether  it  contains  anything  that  must  be  con- 
sidered. Until  this  has  been  done,  logic  can  pass  no 
judgment  upon  the  reliability  of  the  resemblance.  It 
may  be  an  important  resemblance  or  it  may  not  be. 
If  an  important  difference  is  found,  the  resemblance, 
as  has  been  shown,  is  worthless.  If,  however,  a  care- 
ful scrutiny  of  the  new  context  reveals  no  circum- 
stance which  neutralizes  the  force  of  the  analogy, 
the  latter  can  claim  a  certain  measure  of  probability; 
the  degree  of  probability  depending  upon  the  extent 
to  which  it  is  possible  to  eliminate  reasonable  doubt. 

This  scrutiny,  however,  of  the  new  context  serves 
to  make  us  understand  better  the  nature  of  the  re- 
semblance in  question.  Thus  it  may  bring  to  light 
further  resemblances  which  point  to  the  same  con- 
clusion. "  In  the  argument  from  analogy  we  [may] 
put  together  a  number  of  little  points  of  likeness 
between  case  A  and  ease  B  and  (rightly  or  wrongly) 
judge  the  total  likeness  sufficient.  The  Panama  Canal 
resembled  the  Suez  Canal  in  various  evident  ways — ■ 
amongst  others  in  being  schemed  by  M.  de  Lesseps; 
and,  no  doubt,  among  other  bits  of  loose  generaliza- 
tion that  the  unlucky  investors  put  together  was  one 
to  the  effect  that '  Whatever  M.  de  Lesseps  undertakes 
is  likely  to  succeed.'  "  * 

In  general,  then,  it  may  be  said  that  if  an  analogy 
can  maintain   itself  against  criticism,   it  establishes 
some  measure  of  probability.    This  probability,  how- 
ever, cannot  be  stated  in  the  satisfying  form  of  per- 
*  Sidgwick,  The  Process  of  Argument,  p.  45. 


166  AN  OUTLINE  OF  LOGIC 

centages,  since  the  probability  is  not  determined  by 
the  study  of  a  class,  but  by  the  examination  of  a 
particular  resemblance.  It  should  be  noticed  also  that 
while  the  probability  may  be  increased  by  the  dis- 
cover}'- of  further  resemblances,  it  comes  short  of 
certainty,  so  long  as  we  have  reason  to  think  that 
all  the  relevant  circumstances  have  not  been  taken 
into  consideration.  In  the  comparison  of  the  Panama 
and  Suez  canals,  we  know  that  many  important  cir- 
cumstances are  bound  to  be  overlooked.  Here  again 
resemblance  gives  us  the  clue.  Even  though  we  may 
not  be  well  informed  on  the  subject  of  canal  building, 
it  is  like  other  large  enterprises  in  that  it  involves 
man}^  factors  which  cannot  be  determined  in  advance. 
The  knowledge,  therefore,  that  our  analysis  is  not 
complete  justifies  or  motivates  a  doubt,  i.e.,  it  estab- 
lishes a  certain  measure  of  probability  for  an  adverse 
conclusion.  Hence  we  can  at  best  only  conclude  that 
the  inference  is  probably  correct.  A  motivated  doubt, 
as  we  are  now  able  to  define  it,  is  a  doubt  that  can 
'point  to  some  fact  which  seems  to  establish  an  analogy 
or  a  general  rule  as  a  basis  for  the  doubt.  Wherever 
a  motivated  doubt  is  still  possible,  we  have  not  escaped 
from  the  region  of  probability.  It  is  probability, 
whether  the  matter  in  hand  concerns  a  universal  con- 
nection, a  causal  connection,  or  a  question  of  in- 
dividual fact;  and  the  probability  is  necessarily  based 
either  upon  class  resemblance  or  upon  analogy. 

The  Relation  of  Analogy  to  Circumstantial  Evi- 
dence.— According  to  the  foregoing  account,  our 
natural  tendency,  in  dealing  with  a  new  kind  of  case, 
is  to  look  for  resemblances  between  it  and  things 
with  which  we  are  already  familiar.     Such  compari- 


PROBABILITY  167 

sons  we  usually  call  analogy.  It  may  happen,  how- 
ever, that  our  inference  involves  a  comparison  with 
a  number  of  different  things.  For  example,  in  esti- 
mating the  merits  of  a  football  team,  we  may  com- 
pare it  with  several  other  teams,  and  our  inference 
may  thus  be  based  upon  a  series  of  comparisons.  One 
comparison  may  convince  us  that  our  team  has  an 
advantage  in  speed,  another  that  it  has  an  advantage 
in  weight,  a  third  that  it  has  an  advantage  in  su- 
perior training,  and  so  on.  From  these  comparisons, 
taken  collectively,  we  may  infer  that  our  team  is 
likely  to  win  the  championship.  When  inference  is 
thus  based  upon  a  variety  of  different  resemblances, 
i.e.,  when  the  evidence  is  thus  pieced  together  from 
different  sources,  we  tend  to  call  it  circumstantial 
evidence.  In  both  analogy  and  circumstantial  evi- 
dence we  deal  with  cases  which  cannot  be  settled 
by  reference  to  a  class.  The  inferences  are  based 
upon  resemblances,  and  each  resemblance  involves  a 
'  rough  '  or  '  loose  '  generalization.  The  distinguish- 
ing feature  of  analogy,  as  here  defined,  is  that  it  draws 
its  resemblances  from  the  single  parallel  case  or  class 
of  cases  which  is  regarded  as  analogous;  whereas  in 
circumstantial  evidence  the  resemblances  are  derived 
from  various  sources.  It  may  be  that  no  single  case 
can  be  found  which  constitutes  an  exact  parallel  to 
the  case  under  consideration. 

Analogy,  then,  passes  into  circumstantial  evidence  if 
different  analogies  are  combined  to  support  a  conclu- 
sion. This  transition  to  circumstantial  evidence  may 
also  be  indicated  if  we  approach  the  matter  from  the 
side  of  classification.  It  was  stated  above  (p.  155)  that 
estimates  of  probability  are  made  more  accurate  by 


1G8  AN  OUTLINE  OF  LOGIC 

subdivision  of  the  class.  This  subdivision  is  accom- 
plished by  taking  into  consideration  a  greater  number 
of  circumstances  or  resemblances  that  point  to  the  same 
conclusion.  If,  however,  we  continue  to  do  this,  our 
judgment  of  probability  is,  in  the  end,  determined  less 
by  the  behavior  of  the  class  than  by  the  combination  of 
resemblances.  If  we  go  far  enough,  the  class  is  finally 
reduced  to  a  single  member,  i.e.,  we  rely  no  longer  upon 
classification,  but  upon  circumstantial  evidence.  We 
pass  from  the  one  to  the  other  without  a  break.  Cir- 
cumstantial evidence,  then,  differs  from  simple  classi- 
fication only  in  the  fact  that  the  combination  of 
resemblances  is  unique.  In  the  trial  of  criminal  cases, 
for  example,  it  is  not  possible  to  decide  a  particular 
case  by  simply  putting  it  under  a  general  rule,  but 
each  case  must  be  tried  on  its  own  merits,  i.e.,  each 
case  presents  its  own  peculiar  difference.  The  differ- 
ence, however,  may  lie  mainly  in  the  combination  of 
the  circumstances.  Taken  separately,  these  circum- 
stances may  be  very  familiar  to  us ;  and  if  so,  each  one 
involves  a  simple  classification. 

Incidentally  we  may  also  note  that  these  various 
familiar  resemblances  may  be  '  felt  '  before  they  are 
clearly  defined.  As  was  shown  in  the  discussion  of 
class  names  (c/.  Chapter  II),  our  feelings  outrun  our 
powers  of  analysis.  "  Saturated  with  experience  of 
a  particular  class  of  materials,  an  expert  intuitively 
knows  whether  a  newly-reported  fact  is  probable  or 
not,  whether  a  proposed  hypothesis  is  worthless  or 
the  reverse.  He  instinctively  knows  that,  in  a  novel 
case,  this  and  not  that  will  be  the  promising  course 
of  action.  The  well-known  story  of  the  old  judge 
advising  the  new  one  never  to  give  reasons  for  his 


PROBABILITY  169 

decisions,  '  the  decisions  will  probably  be  right,  the 
reasons  will  surely  be  wrong,'  illustrates  this.  The 
doctor  will  feel  that  the  patient  is  doomed,  the  dentist 
will  have  a  premonition  that  the  tooth  will  break, 
though  neither  can  articulate  a  reason  for  his  fore- 
boding. The  reason  lies  imbedded,  but  not  yet  laid 
bare,  in  all  the  countless  previous  cases  dimly  sug- 
gested by  the  actual  one,  all  calling  up  the  same 
conclusion,  which  the  adept  thus  finds  himself  swept 
on  to,  he  knows  not  how  or  why."  * 

*  James,  Psychology,  Vol.  II.,  p.  365. 


CHAPTER  XII 

CIRCUMSTANTIAL  EVIDENCE  AND  THE  TEST 
OF  TRUTH 

The  Nature  of  Circumstantial  Evidence. —  The  re- 
lation of  circumstantial  evidence  to  other  forms  of 
inference  has  already  been  indicated  in  the  preceding 
chapter.  If  an  inference  relies  upon  a  resemblance 
that  is  newly-seen,  rare,  or  doubtful,  it  is  called 
an  inference  from  analogy;  if"  it  is  made  upon  the 
basis  of  an  established  classification,  it  is  called  an 
inference  from  a  generalization ;  if  it  involves  a 
variety  of  resemblances  so  combined  as  to  bear  upon 
a  single  point,  it  is  usually  or  frequently  called  an 
inference  from  circumstantial  evidence.  For  our  pur- 
poses, therefore,  circumstantial  evidence  is  sufficiently, 
though  somewhat  loosely,  defined  if  we  say  that  it  is 
a  combination  of  resemblances. 

In  ordinary  usage  the  term  circumstantial  evidence 
is  applied  most  frequently  to  a  kind  of  evidence 
employed  in  the  trial  of  criminals.  For  example,  a 
house  has  been  robbed  during  the  night.  Smith  has 
been  seen  hanging  around  the  place  on  the  preceding 
day ;  some  of  the  plunder  is  found  in  his  possession ; 
his  boots  fit  the  footprints  under  the  window;  and 
a  glove  that  was  dropped  in  the  house  is  proved  to 
belong  to  him.    Although  no  one  saw  the  act,  evidence 

170 


CIRCUMSTANTIAL  EVIDENCE  171 

of  this  sort  may  be  strong  enough  to  warrant  a  con- 
viction. Each  of  the  resemblances,  if  taken  by  itself, 
may  create  but  a  small  presumption;  together  they 
may  form  a  chain  too  strong  to  be  broken.  The  man 
who  loafs  about  a  place  is  not  necessarily  the  man 
who  committed  the  crime ;  the  man  who  has  possession 
of  the  stolen  property  is  not  necessarily  the  thief ;  the 
man  whose  boots  fit  the  footprints  is  not  necessarily 
the  man  who  made  those  footprints;  and  the  man 
who  owns  the  glove  is  not  necessarily  the  man  who 
dropped  it  where  it  was  found.  Frequently,  indeed, 
this  is  the  case;  i.e.,  each  detail  involves  a  loose  gen- 
eralization. It  may  happen,  however,  that  the  differ- 
ent circumstances  do  not  avail  for  the  inference  if 
taken  separately,  but  only  in  conjunction  with  each 
other.  Thus  we  may  think  nothing  of  the  fact  that 
a  man  supports  his  family  on  a  scale  of  $2,000  a  year. 
Nor  is  the  possession  of  an  expensive  automobile  an 
indication  of  moral  depravity.  Nor  again  is  a  posi- 
tion in  a  bank  at  an  annual  salary  of  $1,000,  without 
any  other  visible  means  of  support,  in  itself  peculiarly 
striking  and  significant.  If,  however,  these  various 
circumstances  happen  to  be  combined  in  the  same  in- 
dividual, the  case  is  different.  Collectively  they  may 
produce  an  impression  which  singly  they  do  not  even 
suggest,  i.e.,  the  circumstances  constitute  a  resem- 
blance only  when  in  combination.  Circumstantial 
evidence  covers  both  kinds  of  cases.  Our  present  task 
is  to  study  this  form  of  reasoning,  in  order  to  become 
acquainted  with  its  methods  and  to  bring  to  light  the 
test  of  truth  which  it  presupposes. 

The  nature  of  circumstantial  evidence  is  best  studied 
in  connection  with  concrete  arguments.    The  preced- 


172  AN  OUTLINE  OF  LOGIC 

ing  discussion  has  made  it  clear  that  the  type  of 
reasoning  called  circumstantial  evidence  is  not  con- 
fined to  courtroom  procedure.  It  is  employed  quite 
as  extensively  in  debate,  in  scientific  proof,  and  in 
everyday  reasoning.  As  a  matter  of  convenience,  the 
examples  to  be  employed  will  be  taken  from  these 
other  fields. 

Examples:  I.  The  first  of  our  examples  may  be 
considered  an  illustration  of  the  procedure  commonly 
adopted  in  debate.  Incidentally  it  also  exemplifies  the 
force  of  unanalyzed  resemblance.  The  argument  oc- 
curs in  a  magazine  article  entitled,  '  Some  Reasons 
why  the  American  Republic  may  Endure.'*  To  the 
average  American  citizen,  it  seems  safe  to  say,  a 
parade  of  evidence  on  this  point  is  not  exactly  the 
fulfilment  of  an  urgent  need.  He  is  only  too  ready 
to  take  the  whole  matter  for  granted,  and  the  less 
reflective  he  is,  the  more  this  is  likely  to  be  the  case. 
In  part  this  is  doubtless  due  to  the  fact  that  the 
question  was  never  really  brought  to  his  attention. 
But  even  if  the  fate  of  other  republics  is  pointed  out, 
he  is  inclined  to  look  upon  the  present  case  as  differ- 
ent. The  American  Republic  is  somehow  so  robust 
and  big  and  solid  that  its  destruction  seems  scarcely 
more  than  a  remote  possibility.  The  reasons,  how- 
ever, why  its  history  should  be  different  from  that 
of  other  republics  are  not  easily  given;  and  even 
if  some  are  offered,  there  is  apt  to  be  a  feeling  that 
they  do  not  do  justice  to  the  facts.  In  a  number  of 
ways  the  American  Republic  suggests  durability,  but 
we  may  find  it  difficult  to  specify  just  what  they  are. 
The  article  mentioned  aims  to  perform  the  necessary 
*  Forum,  Vol.   18,  pp.   129-145. 


CIRCUMSTANTIAL  EVIDENCE  173 

analysis  by  setting  forth  in  detail  the  attributes  of 
the  American  Republic  which  make  for  durability. 
A  brief  enumeration  of  the  main  reasons  that  are 
advanced  will  suffice  for  present  purposes.  They  are : 
(1)  Toleration  in  religion,  which  promotes  mutual 
understanding  and  goodwill;  (2)  Universal  education, 
which  stimulates  interest  in  public  affairs;  (3)  Purer 
family  life,  which  elevates  the  moral  tone  of  a  nation ; 
(4)  Greater  concern  for  public  happiness,  as  expressed 
in  the  maintenance  of  parks,  museums,  and  other 
public  institutions  that  tend  to  prevent  public  dis- 
content; (5)  Publicity,  which  makes  wrongdoing  more 
difficult;  (6)  Loftier  ideals  of  individual  worth  and 
freedom. 

The  argument,  it  will  be  seen,  does  not  rely  upon 
any  single  resemblance,  but  upon  a  combination  of 
resemblances.  Each  of  these  resemblances  involves  a 
generalization,  such  as,  '  Toleration  in  religion  makes 
for  permanence, '  '  Universal  education  makes  for  per- 
manence,' etc.  Each  of  these  generalizations  bears 
upon  the  same  point.  The  probability,  however,  which 
each  of  these  generalizations  is  able  to  create  by  itself 
is  very  slight,  because  the  generalizations  are  true 
only  in  the  abstract,  or  '  other  things  equal.'  Hence 
we  put  together  as  many  such  generalizations  as  pos- 
sible, in  order  to  heighten  the  probability.  Under- 
lying the  entire  argument  is  a  complex  generalization 
to  which  we  must  look  for  justification  of  whatever 
degree  of  probability  we  may  feel.  This  generaliza- 
tion is  to  the  effect  that  '  Wherever  conditions  A,  B, 
C,  D,  etc.,  are  present,  we  may  expect  permanence.' 
The  argument,  therefore,  may  be  stated  in  syllogistic 
form  as  follows: 


174  AN  OUTLINE  OF  LOGIC 

Governments  that  have  (1)  Toleration  in  religion, 
(2)  Universal  education,  etc.,  etc.,  are  governments  that 
are  likely  to  endure; 

This  is  a  government  that  has  (1)  Toleration  in  religion. 
(2)  Universal  education,  etc.,  etc.; 

Therefore  this  government  will  endure. 

Since  our  present  business  is  with  the  combination 
of  resemblances,  the  question  for  our  special  considera- 
tion, in  connection  with  the  present  argument,  is  this : 
On  what  grounds  are  we  entitled  to  assume  that  in 
all  cases  where  the  resemblances  enumerated  in  the 
major  premise  are  present  collectively,  we  may  assert 
1  permanence  '?  This  major  premise  is  a  universal 
proposition;  but  it  is  evident  that  its  truth  cannot 
be  proved  by  the  method  of  varying  all  the  irrelevant 
circumstances,  i.e.,  by  the  Method  of  Agreement.  The 
available  cases  are  not  sufficiently  numerous  to  make 
this  method  applicable.  For  the  same  reason  it  is 
impossible  to  estimate  the  probability  of  this  par- 
ticular case  in  terms  of  ratios.  "We  must,  therefore, 
rely  upon  a  different  mode  of  proof. 

The  form  of  proof  involved  in  this  argument  has 
already  been  indicated  in  the  discussion  of  analogy. 
It  was  there  pointed  out  that  an  analogy  can  claim  a 
certain  measure  of  probability,  if  a  scrutiny  of  the 
surrounding  circumstances  fails  to  reveal  any  fact 
which  upsets  the  claim,  i.e.,  a  fact  which  points  to 
a  different  conclusion.  If,  therefore,  we  assume  that 
the  resemblances  which  we  find  in  the  present  case 
all  point  to  the  same  result,  it  may  rightly  be  claimed 
that  a  preponderance  of  probability  has  been  estab- 
lished. It  is  not  claimed  that  the  resemblances  in 
question  exclude  all  ground  for  doubt.    We  know  too 


CIRCUMSTANTIAL  EVIDENCE  175 

well  that  the  life  of  a  nation  is  dependent,  in  a  large 
measure,  upon  conditions  which  cannot  possibly  be 
predetermined.  The  analogy  of  other  nations  is  a 
legitimate  ground  for  doubt,  and  forbids  complete 
confidence  in  the  conclusion. 

In  this  presentation  it  is  assumed,  for  the  sake  of 
simplicity,  that  all  the  discoverable  resemblances  point 
the  same  way,  and  that  the  only  warrant  for  doubt 
lies  in  the  obvious  incompleteness  of  our  knowledge. 
Such  simplification,  however,  is  rarely  warranted  in 
serious  matters.  In  subjects  that  are  proper  subjects 
for  debate,  some  of  the  resemblances  are  found  to 
point  in  one  direction,  while  others  point  in  another. 
It  therefore  becomes  necessary  to  balance  probabilities 
as  best  we  can.  This  task  is  one  for  which  logic  can 
lay  down  no  rules,  since  each  case  is  unique.  Logic 
can  only  insist  (1)  that  every  resemblance  must  be 
allowed  to  count  as  evidence,  unless  its  force  is  neu- 
tralized by  criticism;  (2)  that  if  all  the  discoverable 
resemblances  give  their  support  to  our  inference,  we 
are  justified  in  asserting  that  a  preponderance  of 
probability  has  been  established;  (3)  if  there  is  evi- 
dence on  both  sides,  we  must  determine  the  pre- 
ponderance of  probability  as  well  as  we  can,  without 
the  aid  of  any  set  rules.  Whenever  we  are  called 
upon  to  compare  probabilities,  personal  idiosyncracies, 
and  the  perception  of  undefined  resemblances  are 
bound  to  play  a  part. 

It  must  be  added  that  while  the  truth  of  our  con- 
clusion is  dependent  upon  the  truth  of  our  major 
premise,  it  is  not  customary,  in  the  type  of  argument 
just  considered,  to  single  out  the  major  premise  so 
explicitly  for  special  consideration.     As  a  rule,  at 


176  AN  OUTLINE  OF  LOGIC 

least,  the  syllogistic  form  is  not  only  awkward,  but 
useless  in  circumstantial  evidence,  and  is  therefore 
left  unexpressed.  Since  the  major  premise  does  not 
apply  to  a  considerable  number  of  cases — its  applica- 
tion may,  indeed,  be  limited  to  a  single  case — its  truth 
is  not  usually  known  in  advance.  We  cannot,  there- 
fore, appeal  to  the  major  premise  in  order  to  prove 
the  present  instance,  but  the  premise  itself  must 
be  proved  by  a  consideration  of  the  individual  re- 
semblances. In  effect,  therefore,  we  prove  both  the 
major  premise  and  the  individual  instance  by  the 
same  process,  and  consequently  we  gain  nothing  by 
distinguishing  between  the  two  and  by  reducing  the 
argument  to  the  form  of  a  syllogism. 

II.  The  mode  of  proof  in  the  preceding  argument 
is  in  principle  the  same  as  the  one  adopted  in  the 
arguments  for  the  theory  of  evolution,  although  the 
two  arguments  differ  greatly  in  strength.  One  of 
the  commonest  facts  in  everyday  life  is  the  influence 
of  heredity.  Now  comparative  anatomy  shows  a  re- 
markable resemblance  in  the  structure  of  animals  as 
widely  different  from  each  other  as  the  whale,  the 
bat,  the  horse,  and  man.  This  resemblance  suggests 
heredity  or  community  of  origin.  The  suggestion 
finds  support  in  paleontology,  or  the  study  of  fossils. 
It  is  found  that  if  the  remains  of  certain  animals, 
notably  those  of  the  genus  horse,  are  placed  in  a 
series  corresponding  to  the  temporal  order  in  which 
the  individual  animals  appeared  upon  the  earth,  the 
whole  series  of  forms  leads  up,  by  successive  steps, 
to  the  forms  with  which  we  are  familiar  to-day.  Here 
again  heredity  is  suggested.  Moreover,  if  we  trace 
back   different  lines  of   descent,   we   find  that  they 


CIRCUMSTANTIAL  EVIDENCE  177 

show  a  certain  approximation  to  the  same  type  of 
structure,  which  again  points  to  evolution. 

A  further  analogy  is  found  in  the  facts  of  embry- 
ology. The  embryo  animal  passes  through  a  series 
of  forms  which  correspond  roughly  to  what  other 
evidence,  particularly  paleontology,  shows  to  have 
been  the  course  of  evolution.  Apparently  we  have 
here  a  case  of  heredity.  And,  lastly,  the  geographical 
distribution  of  living  beings  looks  like  evolution.  The 
number  of  new  species,  both  of  animals  and  of  plants, 
that  are  found  in  a  given  territory,  varies,  in  a  general 
way,  with  the  isolation  of  that  territory.  Far  distant 
islands  have  an  unusual  number  of  distinct  animals 
and  plants.  This  suggests  that  the  forms  were  origin- 
ally alike,  but  that,  being  placed  under  different  con- 
ditions, after  they  had  in  some  way  reached  these 
isolated  regions,  they  developed  in  different  directions. 
In  short,  all  the  facts  here  mentioned  go  to  prove 
evolution,  because  they  seem  to  bear  an  essential  re- 
semblance to  the  facts  of  heredity.* 

The  facts  just  cited  constitute  resemblances  in  the 
sense  that  they  are  the  kind  of  facts  which  we  might 
expect  to  find  if  we  should  assume  that  evolution 
is  true.  They  resemble  the  facts  of  heredity.  This 
being  the  case,  it  is  not  strange  that  it  should  some- 
times be  possible  to  foretell  the  facts  before  they  are 
found.  If  man  descended  from  the  lower  animals, 
then,  according  to  the  laws  of  heredity,  we  are  en- 
titled to  look,  in  man,  for  the  traces  of  certain 
structures  which  were  present  in  these  lower  animals. 

*  Cf.  Romanes,  Darivin  and  After  Darwin,  Vol.  I.,  Chapters 
on  Morphology,  Embryology,  Paleontology  and  Geographical 
Distribution. 


173  AN  OUTLINE  OF  LOGIC 

Accordingly,  "  the  prediction  was  hazarded,  by  an 
older  comparative  anatomy,  that  in  the  embryonic 
state,  he  [man]  would  be  found  with  13  or  14  [pairs 
of  ribs].  This  prophecy  has  since  been  verified.  It 
was  also  predicted  that  at  this  early  stage  he  would 
be  found  to  possess  the  insignificant  remnant  of  a 
very  small  bone  in  the  wrist,  the  so-called  os  centrale, 
which  must  have  existed  in  the  adult  condition  of 
his  extremely  remote  ancestors.  This  prediction  has 
also  been  fulfilled. ' '  * 

The  facts  thus  predicted,  it  may  be  noticed,  were 
not  facts  that  were  still  to  come  into  being  in  the 
future,  but  facts  that  were  to  be  discovered  in  the 
future,  although  they  had  come  into  being  in  the 
past.  Facts  that  are  still  to  occur  cannot  be  pre- 
dicted with  any  great  degree  of  certainty,  unless  the 
circumstances  are  relatively  simple,  so  that  the  condi- 
tions are  well  known.  Hence  the  prediction  of  facts 
that  are  still  to  happen  is  eminently  successful  only 
when  the  conditions  are  sufficiently  under  our  control, 
as  in  scientific  experiments.  In  other  situations  there 
is  constant  danger  that  the  result  will  be  modified  by 
factors  which  cannot  be  foreseen.  For  this  reason 
prophecy  is  shunned  by  the  wise.  Where  prediction 
can  be  verified,  it  merely  serves  the  purpose  of  direct- 
ing our  attention  to  further  resemblances  and  is  not 
a  special  form  of  proof.  If  only  the  resemblances 
that  are  necessary  for  proof  come  to  hand  and  their 
significance  is  understood,  it  does  not  matter  in  the 
least  whether  they  were  predicted  or  discovered  by 
accident,  f 


*  Drummond,   The  Ascent  of  Man,  p.  96. 

f  That  the  ability  to  predict   is  not  necessarily  conclusive 


CIRCUMSTANTIAL  EVIDENCE  179 

If  we  compare  the  argument  for  evolution  with  the 
argument  for  the  stability  of  the  American  Republic, 
we  find  that  the  one  deals  with  the  past  while  the 
other  deals  with  the  future.  This  alone  is  an  im- 
portant difference,  because,  as  has  just  been  indicated, 
the  inference  from  cause  to  effect  is  hazardous,  unless 
we  are  protected  against  the  influence  of  causes  which 
we  are  unable  to  foresee.  But  the  inference  from 
effect  to  cause  is  a  different  matter.  In  this  latter 
case  we  have  the  great  advantage  that  we  need  not 
consider  any  possible  causes,  except  such  as  have  left 
some  record  or  imprint  of  their  presence.  To  suggest 
such  other  causes  would  be  unmotivated.  Now,  ac- 
cording to  the  advocates  of  evolution,  the  facts  all 
point  to  origin  by  descent  as  their  explanation,  and, 
moreover,  this  is  the  only  explanation  which  is  speci- 
fically pointed  out.  If  this  is  the  case,  it  would  plainly 
be  unwarranted,  or  unmotivated,  to  treat  all  these 
resemblances  as  accidents,  and  their  conjunction  as 
a  mere  coincidence.  In  view  of  the  number  and 
variety  of  these   resemblances,   the   probability  that 

evidence    appears   when   we   consider   the    syllogism    which    it 
implies.     Syllogistically  the  prediction  cited  above  would  read: 

If  evolution  is  a  fact,  the  embryo  possesses  the  characters  x,  y,  z ; 
But  the  embryo  does  possess  these  characters ; 
Therefore  evolution  is  a  fact. 

It  is  evident  that  this  argument  involves  the  fallacy  of 
affirming  the  consequent.  We  do  not  have  complete  proof 
until  we  are  able  to  convert  the  major  premise  and  say, 
'If  the  characters  x,  y,  z  are  present,  evolution  is  a  fact.' 
This  proposition,  however,  is  uncertain,  unless  we  find  further 
resemblances  which,  collectively,  are  sufficient  to  exclude 
reasonable  doubt.  If,  on  the  other  hand,  we  avoid  the 
syllogistic  fallacy  by  adopting  as  our  minor  premise,  '  But 
evolution  is  a  fact,'  it  is  evident  that  this  premise  assumes 
what  is  to  be  proved.  The  main  service  of  prediction  for  proof 
is,  therefore,  to  direct  us  in  the  finding  of  important 
resemblances. 


180  AN  OUTLINE  OF  LOGIC 

they  should  merely  happen  to  occur  as  they  do,  is 
reduced  to  a  minimum.  If  the  letters  of  the  alphabet 
were  combined  at  random,  words  might  be  formed 
occasionally,  but  to  suppose  that  a  Shakespearean 
play  could  be  formed  in  this  way,  would  hardly  be 
an  admissible  hypothesis. 

III.  In  both  of  the  above  arguments  the  inference 
is  founded  upon  a  number  of  resemblances,  each  of 
which  pointed  to  the  conclusion.  It  may  happen, 
however,  that  some  of  the  resemblances  serve  mainly 
to  suggest  some  other  resemblance,  which,  if  it  can 
be  found,  will  bear  the  main  burden  of  the  proof. 
An  example  of  this  is  Franklin 's  proof  that  lightning 
is  electricity.  This  view  commended  itself  to  him 
at  the  outset  on  account  of  the  numerous  resemblances 
between  the  two.  "  Lightning  travels  in  a  zig-zag 
line,  said  he,  and  so  does  an  electric  spark ;  electricity 
sets  things  on  fire,  so  does  lightning ;  electricity  melts 
metals,  so  does  lightning.  Animals  can  be  killed  by 
both,  and  both  cause  blindness;  electricity  always 
finds  its  way  along  the  best  conductor,  or  the  sub- 
stance which  carries  it  most  easily,  so  does  lightning; 
pointed  bodies  attract  the  electric  spark,  and  in  the 
same  way  lightning  strikes  spires  and  trees  and  moun- 
tain tops.  Is  it  not  most  likely  that  lightning  is 
nothing  more  than  electricity  passing  from  one  cloud 
to  another  just  as  an  electric  spark  passes  from  one 
substance  to  another  ?  "  * 

This  array  of  resemblances  raised  a  considerable 
presumption  in  favor  of  the  view  advocated  by  Frank- 
lin. The  main  proof,  however,  was  furnished  by  his 
famous  kite  experiment.     If  lightning  is  electricity, 

*  Buckley,  A  Hhort  History  of  "Natural  Science,  pp.  256-7. 


CIRCUMSTANTIAL  EVIDENCE  181 

it  must  be  possible,  with  the  proper  equipment,  to 
draw  this  electricity  to  the  earth.  Hence  the  kite 
was  sent  up  during  a  thunderstorm,  and  a  connection 
was  thus  established  between  the  clouds  and  the  earth. 
To  the  end  of  the  string  by  which  the  kite  was  held 
there  was  tied  a  metal  key.  The  string  was  then 
lengthened  with  some  silk.  Since  silk  is  a  bad  con- 
ductor, the  electricity  would  be  collected  in  the  key, 
instead  of  escaping  through  the  hand  that  held  the 
silk.  It  was  then  found  that  if  the  key  was  touched 
with  the  finger,  the  usual  effects  of  contact  with  elec- 
tricity resulted,  including  the  characteristic  spark. 

The  supposition  that  the  clouds  were  charged  with 
electricity  was  proved  by  this  experiment,  in  the 
sense  that  the  clouds  were  found  to  act  as  if  charged 
with  electricity.  The  evidence  here,  as  in  the  pre- 
ceding illustrations,  rests  upon  resemblance.  The 
present  case  differs,  however,  in  that  one  of  the  re- 
semblances is  so  obviously  more  significant  than  the 
others.  It  is  clear,  therefore,  that  proof  is  not  alto- 
gether a  matter  of  number  of  resemblances,  nor  of 
their  conjunction,  but  that  the  character  of  the  re- 
semblance may  be  of  much  greater  consequence.  Un- 
der certain  conditions  the  presence  of  electricity  in  a 
body  means  that  the  electricity  has  been  transmitted 
from  another  body.  This  rule  having  been  found  true 
in  a  wide  variety  of  laboratory  experiments,  such 
transmission  must  be  assumed  in  the  present  case,  un- 
less it  is  possible  to  point  out  an  important  difference 
in  the  conditions.  The  other  resemblances  are  merely 
supplementary  evidence.  The  peculiar  lurid  color, 
for  instance,  which  is  common  to  both  lightning  and 
electricity,  is  able  to  raise  but  a  slight  presumption, 


182  AN  OUTLINE  OF  LOGIC 

for  while  sameness  of  color  may  mean  identity  of 
kind,  it  more  frequently  does  not. 

In  so  far  as  this  argument  is  based  upon  an  under- 
lying generalization  that  is  applicable  to  a  wide  class 
of  (laboratory)  cases,  it  may  be  classified  as  an  infer- 
ence from  a  generalization.  But  since  the  main  prob- 
lem is  to  determine  whether  the  resemblance  of  con- 
ditions is  trustworthy,  i.e.,  since  the  resemblance  is 
doubtful,  the  inference  seems  to  be,  on  the  whole, 
more  closely  allied  to  analogy  or  circumstantial  evi- 
dence. We  might  justifiably  classify  it  as  analogy, 
since  the  inference  is  based  upon  resemblance  to  a 
class  of  cases.  This  resemblance,  however,  is  fairly 
complex,  and  in  the  process  of  proof  we  bring  the  new 
fact  into  relation  with  a  wide  set  of  other  facts  besides 
those  of  electricity.  The  proof,  therefore,  involves  a 
combination  of  resemblances;  and  our  whole  proced- 
ure is,  so  far  forth,  akin  to  circumstantial  evidence. 
The  example  shows  concretely  how  closely  these  differ- 
ent forms  of  inference  are  related  to  each  other.  At 
their  extremes  they  are  readily  distinguishable,  but 
the  classification  of  border-line  cases  is  a  matter  of 
individual  preference. 

The  Test  of  Truth. — From  the  arguments  just  dis- 
cussed it  is  plain  that  evidence  or  proof  admits  of 
many  degrees.  Some  inferences  are  extremely  proba- 
ble, while  others  are  not.  We  must  now  inquire  more 
closely  than  we  have  hitherto  done,  what  standard 
or  test  we  employ  in  distinguishing  between  the  true 
and  the  false. 

We  may  begin  by  reminding  ourselves  that  when 
we  attempt  to  establish  a  connection  between  A  and 
B,  it  is  never  possible  to  vary  all  the  circumstances 


CIRCUMSTANTIAL  EVIDENCE  183 

but  one,  in  order  to  prove  that  the  connection  is 
universal;  nor  can  we  vary  one  and  only  one  circum- 
stance, in  order  to  prove  a  causal  connection  (cf. 
Chapters  IX  and  X).  To  prove  that  the  cause  which 
makes  the  phosphorus  of  a  match  give  off  light  and 
heat  is  the  friction  of  striking,  we  should  not  find 
it  either  possible  or  necessary  to  show  that  the  friction 
is  the  only  circumstance  which  has  varied.  It  may 
be  that  some  other  circumstance  occurred  at  the  same 
time,  such  as  the  eruption  of  a  volcano  on  a  distant 
island,  or  a  street  fight  in  the  next  block.  What 
we  actually  try  to  do  is  to  vary  those  circumstances, 
one  by  one,  about  which  we  are  in  doubt,  paying  no 
attention  to  the  rest.  Essentially  the  same  procedure 
is  followed  when  we  try  to  prove  that  a  connection 
is  universal.  In  order  to  show  that  all  unsupported 
bodies  fall,  we  do  not  attempt  to  vary  all  the  possible 
colors,  shapes,  and  sizes  of  objects,  nor  do  we  attempt 
to  vary  circumstances  such  as  the  immigration  laws, 
or  a  revolution  in  South  America.  Circumstances  of 
this  kind  are  set  aside  before  our  inquiry  begins, 
because  we  approach  our  problem  with  a  definite  body 
of  information  as  to  the  constitution  of  things. 

We  find,  therefore,  that  previous  experience  nar- 
rows the  range  of  our  investigation  enormously.  The 
term  experience  is  here  used  in  its  widest  sense,  as 
inclusive  of  all  the  information  at  our  disposal.  But 
neither  is  this  previous  experience  attested  by  a  rigor- 
ous application  of  the  respective  Methods;  and  the 
question  therefore  arises  how  knowledge  gets  a  start. 

The  answer  to  this  question  is  not  difficult,  if  we 
remember  that  we  are  born  with  the  tendency  to 
make  generalizations.     If  A  and  B  are  perceived  to 


184  AN  OUTLINE  OF  LOGIC 

occur  simultaneously  or  in  immediate  succession,  we 
tend  to  assume  a  connection.  If  the  connection  seems 
to  hold  good  throughout  a  great  variety  of  facts,  our 
conviction  of  its  genuineness  becomes  strengthened. 
That  heat,  for  example,  expands  bodies  and  that  cold 
contracts  them,  accords  with  a  great  many  diverse 
observations,  such  as  the  lengthening  of  steel  rails  in 
the  summer,  the  ascension  of  smoke,  the  existence  of 
trade  winds  and  ocean  currents,  the  changes  in  the 
density  of  water,  etc.  And  at  the  same  time  we  learn 
that  many  conjunctions  are  merely  accidental.  If 
we  assume  that  heat  affects  the  volume  of  bodies, 
we  cannot  at  the  same  time  attribute  the  change  in 
volume  to  the  noises  of  the  street  or  to  nihilistic 
activities  in  Russia. 

The  fact  that  we  approach  each  new  situation  on 
the  basis  of  previous  experience  carries  with  it  an 
important  implication.  It  was  stated  that  previous 
experience  serves  to  narrow  down  the  range  of  our 
investigation.  The  connection  which  we  seek  must 
be  found  within  a  relatively  small  area,  and  it  is 
only  within  this  area  that  we  attempt  to  vary  all 
the  circumstances,  or  a  single  circumstance,  as  the 
case  may  be.  We  must  now  note  that  when  the 
connection  is  discovered  of  which  we  were  in  search, 
we  incidentally  furnish  a  bit  of  evidence  to  prove 
that  our  preliminary  assumptions  were  correct,  since 
we  have  widened  the  sphere  within  which  these  as- 
sumptions have  been  found  reliable.  On  the  one  hand, 
a  general  background  of  information  is  necessary  in 
order  to  enable  us  to  discriminate  between  connections 
that  are  necessary  and  connections  that  are  accidental, 
and  thus  to  make  possible  the  inference,  on  the  present 


CIRCUMSTANTIAL  EVIDENCE  185 

occasion,  that  A  and  B  are  connected;  and  on  the 
other  hand,  the  new  inference,  in  its  turn,  justifies 
the  conclusions  reached  in  previous  experience.  The 
experiment  with  the  match,  for  example,  strengthens 
our  supposition,  both  that  friction  may  cause  fire,  and 
that  distant  street  brawls  and  volcanic  disturbances 
are  confined  to  the  general  type  of  effects  previously 
ascribed  to  them. 

It  seems  evident,  therefore,  that  the  proof  upon 
which  we  rely  is  not  the  rigorous  application  of  the 
Methods,  but  the  harmony  of  the  present  experience 
with  a  large  body  of  previous  experience.  The  pre- 
vious experience  determines  the  area  within  which 
the  Methods  are  to  be  applied.  In  order  to  criticize 
the  inference  that  A  and  B  are  connected,  it  is  not 
sufficient  to  show  a  lack  of  conformity  to  an  abstract 
ideal  of  proof,  for  the  same  charge  might  be  brought 
against  the  whole  of  our  experience.  In  order  to 
justify  the  doubt,  we  must  point  out  some  specific 
fact  which,  according  to  previous  experience,  justifies 
the  doubt.  As  was  stated  before,  a  doubt  is  unmoti- 
vated, unless  it  can  point  to  some  fact  which  seems 
to  establish  an  analogy  or  a  general  rule  as  a  basis 
for  the  doubt. 

If  we  turn  now  to  circumstantial  evidence,  we  find 
that  it  relies  upon  the  same  test  of  truth.  The  guiding 
principle  is  resemblance,  which  means  that  we  attempt 
to  harmonize  the  new  fact  with  our  other  experiences. 
We  have  seen  how  analogy  grows  into  circumstantial 
evidence  by  the  combining  or  piecing  together  of  re- 
semblances, and  how  the  probability  tends  to  increase 
as  the  process  continues.  The  greater  the  number  of 
resemblances  which  are  thus  discovered,  the  more  com- 


186  AN  OUTLINE  OF  LOGIC 

plete  is  the  assimilation  of  the  new  fact  with  previous 
experience.  The  new  fact  may  thus  constitute  the 
focus  of  a  complex  network  of  relations,  like  the 
center  of  a  spider's  web.  We  may  find  that  we  can- 
not doubt  the  new  fact  without  casting  a  doubt  upon 
other  experiences  which  were  supposed  to  be  trust- 
worthy. Thus  we  find  that  if  we  doubt  whether  light- 
ning is  electricity,  we  are  entertaining  a  doubt  which 
can  easily  be  extended  to  the  methods  employed  by 
the  scientist  in  the  laboratory,  when  he  is  engaged 
in  the  study  of  electricity.  Circumstantial  evidence, 
therefore,  derives  its  strength  from  the  support  of 
the  great  mass  of  other  experiences  to  which  the  new 
fact  is  assimilated,  and  it  rightfully  denies  a  hearing 
to  all  doubt,  except  the  motivated  kind.* 

It  is  plain,  then,  that  the  test  of  truth  upon  which 
we  rely  in  all  these  forms  of  inference  is  the  con- 
vergence of  evidence.  When  a  vast  body  of  facts 
converges  upon  a  single  point  in  such  a  way  that  no 
room  remains  for  a  motivated  or  reasonable  doubt, 
we  possess  the  best  evidence  that  it  is  possible  to 
obtain.  The  previous  knowledge  then  guarantees  to 
us  the  correctness  of  the  new  inference,  and  the  latter 
on  its  part  proves  the  trustworthiness  of  the  former 
knowledge.  A  doubt  of  the  one  then  involves  a  doubt 
of  the  other.  Taken  in  relative  isolation,  an  infer- 
ence may  be  criticized  with  ease,  but  when  taken  in 
connection  with  other  inferences,  it  may  be  invincible; 
and  the  political  motto,  '  United  we  stand,  divided  we 
fall,'  has,  therefore,  a  peculiar  appropriateness  as 
applied  to  inferences. 

*  For  an  illustration  of  convergr-nt  evidence  cf.  Tyndall,  The 
Forms  of  }\'ater,  §§  1-8;  also  Atlantic  Monthly,  Vol.  90,  p. 
433,  Article,  "  A  Study  of  Local  Option." 


CIRCUMSTANTIAL  EVIDENCE  187 

If,  however,  the  support  of  previous  experience  is 
necessary  to  guarantee  our  new  inference,  the  question 
naturally  suggests  itself,  how  it  is  ever  possible  to 
prove  that  previous  experience  is  wrong.  The  belief 
that  heavy  bodies  fall  fastest  was  supported  by  a  great 
and  varied  amount  of  evidence,  and  yet  it  has  been 
proved  to  be  false,  for  experiment  shows  that  in  a 
vacuum  all  bodies  fall  at  the  same  rate.*  Likewise 
the  belief  that  the  earth  is  necessarily  flat  was  found 
to  be  untenable  when  new  facts  were  discovered.  In 
these  cases,  it  would  seem,  the  new  facts  were  estab- 
lished not  by  means  of  old  facts,  but  in  spite  of 
them. 

The  difficulty  here  involved  is  more  apparent  than 
real.  While  the  experiment  with  the  vacuum  over- 
throws the  old  belief  as  to  heavy  bodies,  it  also  shows 
that  the  belief  contains  a  certain  amount  of  truth. 
The  experiment  shows  that  heavy  bodies  do  fall  fast- 
est in  a  resisting  medium,  i.e.,  when  air  is  present. 
The  behavior  of  bodies  in  a  vacuum  simply  calls  our 
attention  to  a  circumstance  which  was  previously 
overlooked.  If  we  take  account  of  this  circumstance, 
the  old  fact  and  the  new  fact  are  in  accord  with  each 
other.  In  a  similar  manner  the  Newtonian  theory  of 
gravitation  simply  brings  out  a  circumstance  which 
the  older  view  had  failed  to  consider.  It  is  true  that 
an  object  will  ordinarily  fall  off  the  lower  surface 
of  a  sphere,  but  only  on  condition  that  some  larger 
body  is  near  to  attract  it.  By  '  lower  side  '  we  mean 
merely  the  side  which  is  nearest  this  larger  body. 
"When  this  condition  is  duly  recognized,  the  facts  no 
longer  conflict,  but  support  each  other.  The  older 
*  Cf.  Hobhouse,  The  Theory  of  Knowledge,  pp.  405-6. 


1S8  AN  OUTLINE  OF  LOGIC 

beliefs,  therefore,  are  not  wholly  devoid  of  truth,  but 
rather  require  reinterpretation.  In  general  it  may 
be  said  that  the  complete  refutation  of  an  erroneous 
belief  always  explains  how  this  belief  came  to  be 
entertained.  Such  refutation,  therefore,  not  only  casts 
out  the  erroneous  belief,  but  in  some  way  or  other  uses 
it  to  confirm  the  organized  body  of  our  experience. 

Competing  Explanations. — It  frequently  happens 
that  a  fact  may  be  explained  in  more  than  one  way. 
If  the  two  explanations  cover  the  situation  equally 
well,  but  differ  in  simplicity,  we  adopt  the  one  which 
is  the  simpler.  The  other  one  is  then  rejected  for 
either  of  two  reasons:  (a)  because  it  resorts  to  purely 
imaginary  causes,  when  there  are  known  causes  at 
hand,  which  are  able  to  account  for  the  whole  fact; 
or  (b)  because  it  assumes  a  special  combination  of 
circumstances,  where  a  simpler  explanation  is  equally 
satisfactory. 

By  a  '  purely  imaginary  '  cause  is  meant  a  cause  for 
which  there  is  no  specific  evidence.  The  suggestion 
that  the  planets  are  held  in  their  courses,  not  by  the 
mutual  attraction  of  matter,  but  by  invisible  beings 
who  pull  them  about  in  a  manner  which  happens  to 
accord  with  a  universal  law,  illustrates  the  kind  of 
explanation  which  makes  appeal  to  imaginary  causes. 
If  this  kind  of  explanation  is  to  receive  serious  con- 
sideration, the  door  is  opened  to  all  kinds  of  ab- 
surdities. Considered  merely  as  an  abstract  possi- 
bility, the  relation  between  volition  and  movement  may 
be  a  mere  coincidence.  It  may  be  that  whenever  we 
desired  in  the  past  to  move  an  arm  or  hand,  some  cause 
which  was  quite  unrelated  to  our  desire  happened  to 
produce  just  that  movement  at  just  that  time. 


CIRCUMSTANTIAL  EVIDENCE  189 

To  assume  a  special  combination  of  circumstances 
where  a  simpler  explanation  is  equally  adequate  is  in 
principle  about  as  objectionable  as  to  assume  imagin- 
ary causes,  since  such  assumption  also  lends  itself 
readily  to  abuse.  This  can  be  shown  most  clearly 
where  the  fact  to  be  explained  occurs  with  some  fre- 
quency. If  past  experience  is  to  be  our  guide,  we 
must  assume  that  "  if  a  given  result  involves  a  com- 
plex combination  of  many  antecedents,  it  will  be  rare. 
And  conversely,  if  a  given  '  casual  '  combination  is 
frequent  in  a  given  area,  it  is  more  probably  due 
to  a  '  single  '  cause  .  .  .  than  to  a  combination  of 
causes.  Thus  the  recurrence  of  a  particular  hand  at 
whist  is  vastly  improbable,  owing  to  the  great  com- 
plexity of  the  circumstances  which  produce  it.  And 
conversely,  should  it  recur,  it  is  a  lamentable,  but 
probable  inference,  that  a  single  human  agency  has 
produced  it  in  both  instances.  It  would  require  a 
very  complex  combination  of  undirected  bumpings 
and  rubbings  to  shape  one  piece  of  flint  into  an 
arrow-head,  so  that  arrow-head  flints  so  formed  would 
be  rare.  And  conversely,  if  many  are  found  together, 
the  probabilities  are  great  that  all  the  rubbings  and 
bumpings  that  produced  them  were  due  to  a  single 
connected  cause. ' '  * 

The  reason  why  it  is  not  permissible  to  make  use 
of  imaginary  causes  or  of  causes  which  are  unnec- 
essarily complex  will  be  readily  perceived.  To  use 
such  causes  for  explanation  is  to  violate  the  principle 
that  all  doubt  must  be  motivated.  If  we  set  aside 
the  evidence  for  known  causes,  in  favor  of  causes  for 
which  there  is  no  specific  evidence,  we  arbitrarily 
*  Hobhouse,  The  Theory  of  Knowledge,  p.  311. 


190  AN  OUTLINE  OF  LOGIC 

cast  a  doubt  upon  the  evidence  that  is  at  hand.  If 
the  evidence  tends  to  show  that  the  power  which 
controls  the  movements  of  the  planets  is  the  same  as 
the  power  which  causes  bodies  to  fall,  this  evidence 
cannot  be  rejected  unless  there  is  sufficient  evidence 
on  the  other  side.  Similarly,  the  evidence  of  some 
causal  connection  between  volition  and  movement  is 
of  the  same  kind  as  that  of  any  other  causal  con- 
nection, and,  therefore,  cannot  be  ignored,  unless  we 
are  prepared  to  discredit  other  inferences  as  well. 
And  in  the  same  way,  we  challenge  the  authority  of 
previous  experience,  if  we  insist  upon  a  more  com- 
plex explanation  where  a  simple  one  is  equally  suffi- 
cient.* 

In  deciding  between  competing  explanations,  it  must 
be  remembered  that  the  simpler  is  preferable  only  if 
it  is  equally  competent  to  do  justice  to  all  the  facts 
in  the  case.  Descartes'  theory  that  all  animals  ex- 
cept man  are  merely  cunningly  contrived  machines, 
without  any  consciousness,  is  simpler  than  the  com- 
mon view,  but  it  disregards  the  resemblance  between 
animal  behavior  and  human  actions.     Again  it  may 

*  The  principle  that  doubt  must  be  motivated  is  sometimes 
known  as  the  Law  of  Parsimony,  which  declares  that  "  we 
must  not  assume  the  existence  of  more  things  than  necessary." 
This  law  or  rule  was  formulated  by  a  Franciscan  monk, 
William  of  Occam,  who  died  in  1347;  and  it  is  sometimes 
called  Occam's  Razor,  because  it  cuts  away  explanations  which 
lack  proper  motivation.  Occam's  formulation  was:  Entia  non 
sunt  mulliplicanda  praeter  necessitatem.  By  Occam  the  law 
was  given  a  more  special  application,  but  if  we  give  it  full 
scope,  it  takes  in  all  cases  of  unmotivated  doubt.  For  an 
interesting  application  of  the  law  of  parsimony  cf.  LeConte, 
Elements  of  Geology,  Chapter  III.,  p.  109  (4th  edition),  in 
the  paragraph  entitled  "  Theories  of  Geyser-eruption."  Com- 
pare Mackenzie's  theory  with  the  theory  advanced  by  Bunsen 
and  now  commonly  adopted. 


CIRCUMSTANTIAL  EVIDENCE  191 

be  simpler  to  assume  that  a  suspected  person  is  guilty 
of  a  crime  than  that  the  appearance  of  guilt  is  due 
to  a  fortuitous  combination  of  circumstances;  but 
the  suspicion  may  be  completely  at  variance  with 
what  we  know  about  the  person's  character.  Situa- 
tions constantly  arise  in  which  it  is  impossible  to 
determine  in  any  off-hand  way,  or  according  to  any 
set  rule,  the  preponderance  of  probability,  and  doubt 
is,  therefore,  justifiable. 

The  Function  of  Reasonable  Doubt. — Whenever 
a  reasonable  doubt  is  possible,  the  evidence  is  not  yet 
sufficient.  At  that  particular  point  where  the  doubt 
finds  a  foothold,  experience  does  not  seem  to  support 
our  theory.  We  may  thus  be  uncertain  as  to  the 
identity  of  lightning  and  electricity,  because  in  spite 
of  numerous  resemblances,  the  electricity  of  the  labora- 
tory involves  visible  and  tangible  objects,  whereas 
lightning  does  not.  The  doubt,  therefore,  shows  us 
where  the  argument  is  incomplete ;  and  the  removal  of 
the  doubt  means  that  the  case  under  consideration 
has  been  brought  into  relation  with  a  wider  range  of 
facts.  Thus  the  absence  of  visible  and  tangible  ob- 
jects loses  its  significance  when  it  is  found  that  air- 
currents  can  produce  friction,  and  that  the  invisible 
particles  of  moisture  can  carry  electricity.  This 
means,  of  course,  that  a  new  set  of  facts  has  come  into 
play,  or  that  more  evidence  has  been  made  to  con- 
verge upon  a  given  point.  The  case  under  considera- 
tion has  been  found  to  harmonize  with  a  larger  part 
of  our  total  experience  and  has  gained  a  correspond- 
ing increase  in  probability. 

Probability    and    Certainty.— The    limit    of    this 
process  is  reached,  as  has  already  been  indicated,  when 


192  AN  OUTLINE  OF  LOGIC 

motivated  doubt  is  no  longer  possible.  This  is  the 
stage  of  practical  certainty.  The  distinction  between 
probability  and  certainty  is  one  that  is  recognized 
in  everyday  life.  It  is  not  regarded  as  merely  probable 
that  heat  expands  bodies  or  that  lightning  is  elec- 
tricity. It  is  called  practical  certainty,  because  it 
is  secure  against  all  doubt,  except  the  kind  that  is 
unmotivated.  The  weakest  form  of  probability  is  thus 
connected  by  a  continuous  line  with  the  point  of  cer- 
tainty, where  further  evidence  is  no  longer  required. 
Certainty  is  approximated  as  the  evidence  becomes 
more  convergent.  In  proportion  as  a  belief  stands 
isolated  from  other  beliefs,  it  is  called  a  blind  belief 
or  a  superstition ;  whereas  a  belief  that  possesses  evi- 
dence is  called  to  that  extent  a  rational  belief. 

The  kind  of  certainty  here  discussed  finds  an  inter- 
esting exemplification  in  courtroom  procedure.  The 
following  passage  from  the  instructions  of  a  judge 
to  a  jury  indicates  plainly  the  criterion  of  truth 
that  is  meant  to  be  adopted:  "As  to  the  distinction 
between  reasonable  doubt  and  a  possible  doubt,  you 
were  thoroughly  examined  when  you  were  about  to 
become  jurors.  The  law  does  not  require  that  the 
prosecution  shall  efface  every  possible  doubt.  It  only 
requires  that  the  prosecution  shall  go  beyond  a  reason- 
able doubt.  .  .  .  The  defendant  is  entitled  to  have 
his  guilt  established  by  competent  evidence  and  be- 
yond reasonable  doubt.  It  need  not  be  established 
beyond  all  doubt,  for  that  is  an  impossibility.  Noth- 
ing in  this  world  is  beyond  all  doubt.  The  defendant 
is  entitled  to  every  reasonable  doubt  and  that  is 
all. 

"  A  reasonable   doubt  is  such  a  doubt  as  might 


CIRCUMSTANTIAL  EVIDENCE  193 

arise  in  the  mind  of  an  intelligent  man,  who  if  called 
upon  to  give  a  reason  for  such  a  doubt  would  not 
be  at  a  loss  to  do  so.  A  reasonable  doubt  is  not  an 
imaginary  thing.  It  is  such  a  doubt  as  arises  from 
the  evidence.  It  is  such  a  doubt  as  a  painstaking  man 
might  have  after  a  full,  fair,  and  impartial  weighing 
of  the  evidence.  To  all  such  doubts  the  defendant  is 
entitled. 

"  If  any  of  you  have  a  reasonable  doubt  that  this 
defendant  is  guilty  of  murder  in  the  first  degree, 
but  have  no  doubt  that  he  is  guilty  of  murder  in  the 
second  degree,  you  may  find  in  the  second  degree, 
and  so  with  manslaughter." 

Hypothesis,  Theory,  and  Fact. — It  has  been  shown 
that  all  degrees  of  probability  may  be  realized  between 
the  two  extremes  of  unmotivated  possibility  and  prac- 
tical certainty.  But  although  there  are  no  hard  and 
fast  lines  of  division,  language  recognizes  certain 
stages,  just  as  we  recognize  in  the  life  of  the  individual 
the  stages  of  youth,  maturity,  and  old  age.  These 
different  stages  of  evidence  are  indicated,  though  in 
a  rather  haphazard  fashion,  by  the  terms  hypothesis, 
theory,  and  fact. 

By  hypothesis  is  usually  meant  a  supposition  that 
has  relatively  little  evidence  to  support  it.  Hypotheses 
are  suggested  by  resemblances  and  are  tentative  ex- 
planations. The  supposition,  for  example,  that  all 
the  matter  in  the  universe  once  existed  in  a  gaseous 
state,  is  frequently  called  the  Nebular  Hypothesis. 
For  the  same  reason  a  supposition  which  is  made  in 
order  to  make  a  prediction,  may  be  referred  to  as  a 
hypothesis,  so  long  as  the  prediction  remains  unveri- 
fied,    Thus   Franklin   adopted   the   hypothesis   that 


101  AN  OUTLINE  OF  LOGIC 

lightning  is  electricity,  and  then  proceeded  to  make 
a  deduction  from  this  hypothesis,  in  accordance  with 
the  principles  which  are  formulated  in  the  doctrine  of 
the  syllogism.  Stated  syllogistic  ally,  his  reasoning  was 
as  follows: 

Electricity  behaves  in  a  certain  way  (x)  under  certain 
conditions   (y)  ; 

Lightning  is  electricity; 

Therefore  lightning  will  behave  in  this  way  under  these 
conditions. 

When  the  evidence  in  support  of  a  supposition  is 
relatively  strong,  we  are  more  inclined  to  dignify  the 
supposition  with  the  name  of  theory.  A  hypothesis, 
therefore,  may  become  a  theory,  if  the  predictions 
based  upon  it  are  verified,*  or  if  sufficient  evidence  is 
secured  in  other  ways.  Thus  the  supposition  that 
man  and  other  animals  have  sprung  from  the  same 
source  is  usually  called  the  theory  of  evolution.  The 
terms  hypothesis  and  theory  are,  however,  used  loosely 
and  are  frequently  interchanged. 

When  we  speak  of  fact  we  generally  mean  any- 
thing which,  for  the  purpose  that  we  have  in  view, 
requires  no  proof.  It  marks  the  stage  of  practical 
certainty;  and  the  possibility  of  error,  which  is  sug- 
gested by  terms  like  '  hypothesis  '  and  '  theory, '  is 
supposed  to  be  absent.  Thus  we  say  that  it  is  a  fact 
and  not   '  merely  '   a  theory   that  Washington   was 

*  If  a  hypothesis  is  untenable,  this  may  sometimes  be  made 
evident  by  showing  that  deductions  made  from  it  do  not  tally 
with  the  facts.  Such  refutation  is  sometimes  known  as  re- 
ductio  ad  absurdum.  An  illustration  is  furnished  in  Webster's 
Reply  to  Hayne. 


CIRCUMSTANTIAL  EVIDENCE  195 

the  first  President  or  that  bullet  wounds  may  cause 
death. 

The  Fallacies   of  Circumstantial  Evidence. — We 

have  seen  that  circumstantial  evidence  is  in  principle 
the  same  as  reasoning  from  analogy  or  from  a  general- 
ization, the  difference  being,  in  the  main,  a  difference 
of  complexity.  It  is  to  be  expected,  therefore,  that 
the  fallacies  with  which  we  have  already  become 
familiar  should  recur  in  connection  with  circumstan- 
tial evidence.  If  we  criticize  circumstantial  evidence 
in  detail,  we  may  find,  now  a  false  analogy,  now  a  false 
assumption,  now  a  false  disjunction,  and  so  on.  Each 
successive  criticism  weakens  the  argument  by  so  much. 
There  is,  however,  in  circumstantial  evidence  a  fre- 
quent fault  which,  while  it  may  sometimes  be  classed 
as  a  false  assumption,  usually  goes  by  no  commonly 
accepted  name.  It  consists  in  the  neglect  of  some 
important  aspect  or  circumstance  which,  if  given 
proper  weight,  would  cast  a  doubt  upon  the  conclu- 
sion. The  argument  then  rests  upon  a  false  assump- 
tion, since  it  takes  for  granted  that  all  the  important 
considerations  have  been  taken  into  account.  The 
charge  of  false  assumption,  however,  is  not  made,  be- 
cause by  false  assumption  we  ordinarily  mean  that  the 
truth  of  some  specific  and  questionable  proposition 
has  been  taken  for  granted,  whereas  in  this  case  the 
assumption  is  less  specific.  We  simply  take  for 
granted,  erroneously,  that  all  the  relevant  circum- 
stances have  been  considered.  We  may  call  this 
fallacy  the  fallacy  of  neglected  aspect,  although  the 
term  is  inconveniently  wide.  The  several  circum- 
stances upon  which  the  inference  is  based  do  not 
point  to  the   conclusion  that  is   drawn,   unless  the 


196  AN  OUTLINE  OF  LOGIC 

neglected  aspect — the  aspect  which  points  to  a  differ- 
ent conclusion — is  kept  out  of  sight.  We  therefore 
say  that  the  argument  is  '  true  in  the  abstract/  or 
'  true  as  far  as  it  goes, '  but  that  it  does  not  take 
things  as  they  actually  are.  Hence  the  misleading 
saying  has  arisen,  '  true  in  theory,  but  false  in  prac- 
tice.' This  saying  is  misleading,  because  a  theory 
which  cannot  stand  the  test  of  facts  is  a  false 
theory,  since  it  distorts  the  situation.  It  assumes 
that  the  facts  with  which  it  deals  have  a  cer- 
tain constitution  which  in  reality  they  do  not 
possess. 

As  an  illustration,  we  may  take  this  newspaper 
argument  against  prohibition:  "You  destroy  the  jobs 
of  people  upon  whom  about  5,000  of  the  population 
depend;  you  take  the  jobs  away  from  about  2,000 
room-rent  or  house-rent  payers  or  home  owners; 
you  deprive  the  city  itself  of  about  $300,000  of 
direct  revenue,  in  the  way  of  excise  taxes  and 
property  taxes;  you  depreciate  the  rental  value 
of  about  $5,000,000  worth  of  property  in  the 
town." 

We  may  assume  that  the  assertions  just  quoted  are 
entirely  correct.  If  the  facts  which  they  bring  for- 
ward were  the  only  ones  to  be  considered,  the  infer- 
ence as  to  prohibition  would  be  inevitable.  If,  how- 
ever, the  liquor  traffic  is  as  pernicious  in  its  influ- 
ence as  its  opponents  claim  it  to  be,  the  benefits 
which  result  from  it  are  far  outweighed  by  the  evil 
which  it  produces.  This  aspect  of  the  case  is 
neglected,  however,  and  so  the  argument  remains 
inconclusive. 

Persons  who  are  visionary  or  '  merely  theoretical ' 


CIRCUMSTANTIAL  EVIDENCE  197 

are  particularly  liable  to  the  fallacy  of  neglected 
aspect.  Their  opinions  may  have  a  certain  superficial 
plausibility  or  consistency,  but  we  usually  find  that 
this  is  due  to  the  fact  that  some  important  detail 
or  details  have  been  left  out  of  account.  Thus  ' '  every 
roseate  picture  of  the  happiness  to  be  attained  when 
the  competition  of  commercial  rivals  has  ceased,  and 
the  State  controls  all  industry  and  gives  every  one 
his  due,  is  painted  in  happy  forgetfulness  of  the 
natural  discontent,  selfishness,  or  ambition  which 
would  prompt  most  of  the  people  in  such  a  com- 
munity to  shirk  their  appointed  tasks,  to  use  personal 
influence  in  order  to  get  some  special  privilege,  or 
to  gain  control  of  the  machinery  of  government  for 
the  particular  benefit  of  themselves  and  their  friends 
— forces  in  human  nature  which  would  replace  com- 
mercial competition  with  political  jobbery."* 

*  Aikins,  Principles  of  Logic,  p.  211. 


CHAPTER  XIII 
OBSERVATION  AND  MEMORY 

We  have  seen  that  the  final  test  of  truth  is  the 
mutual  support  which  different  inferences  give  to 
each  other.  If  a  generalization  is  found  to  hold  in 
a  great  number  of  different  applications,  or  if  a 
number  of  generalizations  or  analogies  all  point  to 
the  same  result,  we  consider  ourselves  on  the  road 
to  certainty;  and  when  we  reach  the  point  where 
1  reasonable  '  doubt  is  excluded,  the  goal  has  been 
reached.  What  was  at  first  merely  a  tentative  hy- 
pothesis or  a  plausible  theory,  then  becomes  an  in- 
disputable fact. 

In  this  scheme  facts  appear  as  the  culmination  of 
an  elaborate  process;  and  this  circumstance  is  apt 
to  raise  a  difficulty.  It  is  well  enough  to  reach  facts 
as  the  result  of  our  endeavors,  but  it  would  seem 
that  facts  are  indispensable  as  a  starting-point.  In- 
ference asserts  that  something  is  true  because  some- 
thing else  is  true,  as  when  we  say  that  A  is  B  and 
therefore  it  is  C.  The  inference,  however,  has  no 
great  value  unless  we  know  at  the  outset  that  A  is 
B.  The  apparent  paradox,  then,  is  that  in  order  to 
have  facts  we  must  depend  upon  inference,  while 
inference  in  turn  rests  upon  facts. 

The  Popular  Notion  of  Observation. —  It  is  fre- 
quently supposed  that  the  facts  from  which  infer- 

198 


OBSERVATION  AND  MEMORY  190 

ence  starts  are  not  dependent  upon  inference,  but 
given  in  a  very  different  way.  They  are  derived,  not 
through  the  inferential  processes  underlying  the  con- 
vergent lines  of  evidence,  but  from  the  '  evidence  of 
the  senses.''  Knowledge  starts  with  what  we  im- 
mediately experience,  and  what  we  thus  experience 
is  fact.  The  basis  of  fact  thus  acquired  through 
sense-impressions,  known  collectively  as  observation, 
furnish  us  with  the  material  for  the  various  forms 
of  inference  already  discussed. 

Difficulties  of  This  View. — This  view  is,  in  a  way, 
both  simple  and  plausible.  It  holds  that  facts  are 
of  two  kinds,  those  known  immediately  and  those 
established  by  the  convergence  of  evidence.  Difficul- 
ties appear,  however,  when  we  examine  the  matter 
more  closely.  It  is  soon  found  that  the  term  '  ob- 
servation,' which  is  meant  to  refer  to  facts  that  are 
known  immediately,  is  used  in  a  very  loose  sense. 
It  is  applied  to  many  facts  which  are  not  independent 
of  inference.  We  '  observe,'  for  example,  that  a  man 
is  angry,  or  asleep,  or  proud,  or  indifferent.  But 
wThat  we  actually  see  is,  at  best,  certain  facial  expres- 
sions and  bodily  attitudes.  Again,  we  say  that  we 
observe  the  presence  of  our  friend  or  of  certain  fa- 
miliar objects,  whereas  the  phenomena  of  dreams  and 
hallucinations  show  that  such  observations  may  be 
erroneous.  Or  we  assert  that  we  have  observed  the 
course  of  certain  stars,  the  results  of  tariff  legisla- 
tion, of  religious  intolerance,  etc.  Here  the  element 
of  inference  is  even  more  prominent.  We  do  not 
observe  the  course  of  the  star,  strictly  speaking;  but 
we  note  certain  positions  and  we  infer  that  the  star 
has  moved  along  a  continuous  line  from  one  of  these 


200  AN  OUTLINE  OF  LOGIC 

positions  to  the  other.  As  to  the  tariff  legislation 
and  the  policy  of  religious  intolerance,  we  have  no- 
ticed certain  sequences  and  we  have  inferred  a  causal 
connection.  Common  sense  itself  tends  to  correct  its 
loose  usage  of  the  term  observation.  "When  we  make 
errors  we  do  not  usually  say  that  we  observed  in- 
correctly, but  that  we  '  thought  we  saw.'  It  is  the 
thought  element  or  the  element  of  inference  that  gets 
the  blame. 

This  indiscriminate  use  of  the  term,  however,  does 
not  prove  that  observation  in  the  narrower  sense  does 
not  give  us  facts  immediately  and  just  as  they  are. 
It  merely  suggests  that  there  may  be  difficulty  in  find- 
ing out  what  is  pure  sense-experience  and  what  is 
not.  But  granted  that  there  is  pure  sense-experience, 
the  belief  in  its  trustworthiness  is  apt  to  weaken 
when  we  study  the  processes  which  such  experience 
involves.  Psychology  tells  us  that  sense-experience 
is  due  in  part  to  the  stimulation  of  the  sense-organs 
and  in  part  to  processes  of  association.  A  cake  of 
ice,  for  example,  looks  cold;  the  eye  of  a  snake  looks 
cruel ;  and  a  block  of  granite  may  look  hard  or  heavy. 
In  each  case  the  object  '  looks  '  as  it  does  owing  to 
associations.  Cold  is  not  something  that  can  be  seen, 
since  it  has  neither  color  nor  form,  yet  the  quality 
of  the  visual  perception  has  been  changed  through 
the  experiences  that  have  been  associated  with  this 
perception  in  the  past.  It  is  true  that  such  associa- 
tions usually  suggest  inference  as  well,  but  the  point 
to  be  noted  just  at  present  is  that  the  associations 
change  the  actual  quality  of  the  sense-perception, 
whatever  else  they  may  involve  in  the  way  of  infer- 
ence. 


OBSERVATION  AND  MEMORY  201 

We  find,  then,  that  the  total  observation,  apart  from 
the  element  of  inference,  is  a  compound  of  sense- 
impressions  and  images.  The  images  are  copies  of 
previous  sense-impressions  and  they  blend  into  the 
body  of  the  total  experience  in  such  a  way  as  to 
change  the  character  of  the  sense-impression.  This 
is  why  the  ice  looks  so  cold  and  repellent,  whereas 
a  bale  of  cotton  looks  soft,  downy,  and  inviting.  The 
images  lose  their  individuality  and  become  part  of 
the  bone  and  tissue  of  the  total  experience. 

"  Our  own  language  would  sound  very  different 
to  us  if  we  heard  it  without  understanding,  as  we 
hear  a  foreign  tongue.  Rises  and  falls  of  the  voice, 
odd  sibilants  and  other  consonants,  would  fall  on  our 
ear  in  a  way  of  which  we  can  now  form  no  notion. 
Frenchmen  say  that  English  sounds  to  them  like  the 
gazouillement  des  oiseaux — an  impression  which  it 
certainly  makes  on  no  native  ear.  Many  of  us  Eng- 
lish would  describe  the  sound  of  Russian  in  similar 
terms.  All  of  us  are  conscious  of  the  strong  in- 
flections of  voice,  the  explosives  and  gutturals  of 
German  speech  in  a  way  in  which  no  German  can  be 
conscious  of  them. 

"  This  is  probably  the  reason  why,  if  we  look  at 
an  isolated  printed  word  and  repeat  it  long  enough, 
it  ends  by  assuming  an  entirely  unnatural  aspect.  Let 
the  reader  try  this  with  any  word  on  this  page. 
He  will  soon  begin  to  wonder  if  it  can  possibly  be 
the  word  he  has  been  using  all  his  life  with  that 
meaning.  It  stares  at  him  from  the  paper  like  a 
glass  eye,  with  no  speculation  in  it.  Its  body  is 
indeed  there,  but  its  soul  has  fled.  It  is  reduced, 
by  this  new  way  of  attending  to  it,  to  its  sensational 


202  AN  OUTLINE  OF  LOGIC 

nudity.  We  never  before  attended  to  it  in  this  way, 
but  habitually  got  it  clad  with  its  meaning  the  mo- 
ment we  caught  sight  of  it,  and  rapidly  passed  from 
it  to  other  words  of  the  phrase.  We  apprehended  it, 
in  short,  with  a  cloud  of  associates,  and  thus  perceiv- 
ing it,  we  felt  it  quite  otherwise  than  we  feel  it  now, 
divested  and  alone. ' '  * 

This  being  the  case,  the  question  whether  observa- 
tion in  its  narrower  sense  is  always  reliable,  becomes 
dependent  upon  the  question  whether  the  right  as- 
sociates always  come  up  to  blend  with  what  is  given 
in  sense-impression.  Evidently  this  is  not  the  case. 
Sometimes  it  happens  that  different  sets  of  associa- 
tions come  up  in  succession,  so  that  the  object  changes 
before  our  very  eyes,  as  when  an  object  that  we  take 
to  be  a  man  is  suddenly  seen  as  a  shrub  or  a  post. 
However  erroneous  our  perception,  the  object  may 
be  seen  as  distinctly  as  though  it  were  present.  We 
do  not  merely  '  think  we  see  '  it,  but  we  actually  do 
see  it;  and  this  is  as  true  of  the  other  senses  as  of 
the  sense  of  vision. 

What  is  actually  given  in  sense-impression  is  fre- 
quently but  a  small  fraction  of  the  whole;  as  it  has 
been  put,  most  of  the  seeing  is  done  '  behind  the  eye.' 
We  run  our  eye  over  a  line  of  print  and  recognize 
the  various  words,  not  because  we  pay  attention  to 
each  letter,  as  we  might  do  if  we  were  just  learning 
to  read,  but  because  the  casual  glance  is  enough  to 
arouse  the  associations  which  complete  the  picture. 
If  it  were  not  for  the  associations,  we  should  be 
obliged  to  distinguish  carefully  between  letters  like 
b  and  h,  or  m  and  n,  or  p  and  q.  But  by  means  of 
*  James,  Psychology,  Vol.  II.,  pp.  80-81. 


OBSERVATION  AND  MEMORY  203 

associations,  the  details  are  filled  in  as  they  should 
be.  For  this  reason  we  tend  to  overlook  misprints. 
By  association  the  correct  letter  is  put  in,  so  that 
we  actually  see  what  is  not  there. 

The  effect  of  association  upon  perception  is  shown 
in  a  striking  way  by  the  discrepancies  in  courtroom 
testimony.  "  In  some  Bowery  wrangle,  one  witness 
was  quite  certain  a  rowdy  had  taken  a  beer-mug  and 
kept  it  in  his  fist  while  he  beat  with  it  the  skull  of 
his  comrade;  while  others  saw  that  the  two  were 
separated  by  a  long  table,  and  that  the  assailant  used 
the  mug  as  a  missile,  throwing  it  a  distance  of  six 
or  eight  feet.  In  another  trial,  one  witness  noticed 
at  the  seashore  in  moonlight  a  woman  with  a  child, 
while  another  witness  was  not  less  sure  that  it  was 
a  man  with  a  dog.  And  only  recently  passengers  in  a 
train  which  passed  a  courtyard  were  sure,  and  swore, 
that  they  had  taken  in  at  a  glance  the  distinct  picture 
of  a  man  whipping  a  child;  one  swore  that  he  had 
a  clean-shaven  face,  a  hat,  and  was  standing,  while 
another  swore  that  he  had  a  full  beard,  no  hat,  and 
was  sitting  on  a  bench.  The  other  day  two  most 
reliable  expert  shorthand  writers  felt  sure  that  they 
heard  the  utterances  which  they  wrote  down,  and  yet 
the  records  differed  widely  in  important  points. ' '  * 

How  Association  is  Determined. — The  discus- 
sion of  the  principles  which  control  association  must 
be  left  to  psychology.  In  general,  however,  we  may 
say  that  by  association  we  tend  to  see  things  as  we 
have  seen  them  before.  But  this  is  not  the  whole 
story.  If  we  happen  to  be  expecting  something,  we 
are  apt  to  see  it,  i.e.,  the  corresponding  associations  are 
*  Munsterberg,  On  the  Witness  Stand,  pp.  16-17. 


204  AN  OUTLINE  OF  LOGIC 

likely  to  come  up,  even  if  they  are  not  the  usual  ones. 
"Whether  these  two  principles  of  association  are  the 
only  ones  we  need  not  attempt  to  decide.  Association 
is  primarily  a  question  of  brain  activity ;  and  it  may 
be  that  at  times  one  set  of  associates  comes  up  more 
readily  than  another,  not  because  it  is  the  most  usual 
set,  nor  yet  because  we  are  expecting  a  certain  object, 
but  simply  because  the  matter  is  determined  by  the 
physical  condition  of  the  brain,  such  as  its  state 
of  nutrition  or  exhaustion. 

Memory. —  With  regard  to  memory  the  situation 
is  much  the  same.  As  in  observation,  associations  in- 
evitably come  up  which  so  modify  the  total  experience 
that  it  is  impossible  to  distinguish  the  elements  and 
to  point  out  just  what  it  is  that  we  remember  and 
what  it  is  that  has  been  added  or  changed  by  as- 
sociation. The  elements  are  not  present  in  mere 
juxtaposition,  but,  like  chemical  elements,  have  united 
to  form  a  new  whole  in  which  the  constituents  are 
lost  to  view.  Correct  observations,  therefore,  may 
be  incorrectly  reported  by  memory,  and  incorrect 
observations  are  subject  to  a  further  process  of  dis- 
tortion. 

"  A  classic  instance,  both  of  the  defects  of  our 
memory  and  of  its  general  subjection  to  the  law  of 
assimilation,  is  furnished  by  the  well-known  accounts 
which  older  people  are  accustomed  to  give  of  what 
they  frequently  describe  as  the  '  old-fashioned  win- 
ters '  of  their  childhood.  '  The  winters,'  so  such  a 
person  may  say,  '  are  no  longer  such  as  they  used 
to  be  when  I  was  a  boy.  At  that  time  the  snow 
began  to  fall  in  November,  and  lay  almost  steadily 
until  March.     We  had  sleighing  nearly  all  the  time, 


OBSERVATION  AND  MEMORY  205 

and  especially  at  Christmas.  The  harbor  used  to 
freeze  over.  The  skating  was  almost  steadily  good. 
But  nowadays  the  winters  are  full  of  unsteady 
weather:  there  are  frequent  thaws;  the  sleighing  and 
skating  are  in  no  wise  trustworthy;  the  harbor  al- 
most never  freezes;  in  fine,  the  climate  has  changed.' 
"  That  such  reports  are  in  general  not  confirmed 
by  meteorological  records,  may  and  usually  does  seem 
of  little  importance  to  the  reporters  of  such  reminis- 
cences. His  memory  is  his  own.  Facts  are  facts; 
and  meteorological  science,  he  tells  you,  is  notoriously 
uncertain.  He  prefers  to  trust  his  memory,  which  is 
perfectly  clear  on  the  subject.  Now  what  most  per- 
sons fail  to  notice  is  that  the  '  old-fashioned  winter  ' 
of  such  reminiscences  is,  on  its  very  face,  a  psycho- 
logical and  not  a  meteorological  phenomenon.  The 
human  memory  is  essentially  incapable  of  retaining 
a  series  of  accurate  reports  of  phenomena  so  variable 
and  inconstant  as  those  of  the  weather.  In  such  a 
field  only  general  characteristics  can  be  remembered, 
especially  after  many  years.  How  good  an  account 
can  you  now  give,  from  memory,  of  the  precise 
weather  changes  of  even  the  past  month?  But  even 
general  characteristics  are  themselves  not  accurately 
recorded  by  memory,  in  case  of  the  weather,  as  they 
were  presented  in  fact;  since  we  have  no  cerebral 
habits  that  are  capable  accurately  of  representing 
either  mean  temperatures,  or  amounts  of  snow  fall, 
so  long  as  precise  records  of  these  phenomena  are 
not  kept  at  the  time.  On  the  contrary,  what  we 
retain  in  mind,  especially  from  our  early  youth,  are 
the  memories  of  the  more  interesting  and  significant 
habits  that  winter  weather  formerly  developed  in  us. 


206  AN  OUTLINE  OF  LOGIC 

In  our  memories  the  images  that  survive  are,  for  the 
most  part,  assimilated  by  those  which,  when  we  recall 
the  past,  are  directly  connected  with  our  more  vividly 
recalled  habits.  As  the  youth  formed  his  most  im- 
portant winter  habits  in  connection  with  great  snow- 
storms and  decidedly  cold  weather,  and  as  such  phe- 
nomena occurred  sometimes  early  and  sometimes  late 
in  winter,  and  were  of  special  importance  to  him 
in  holiday  season,  his  memories  were  formed  accord- 
ingly. What  the  old  man  recalls  is  therefore  a  general 
collection  of  interesting  winter  habits,  and  of  images 
clustered  about  them.  These  habits  define  for  his 
consciousness  a  certain  typical  object,  the  '  old- 
fashioned  winter,'  which  presumably  never  existed 
as  he  remembers  it.  The  dreary  individual  detail  of 
the  actual  winters  of  his  boyhood  has  happily  escaped 
his  memory.  But  since  lately,  say  in  the  present 
winter,  he  has  such  dreary  details  forced  upon  his 
present  attention  by  uncomfortable  experiences,  he 
does  indeed  recognize  that  there  is  a  present  state 
of  facts  which  he  cannot  assimilate  to  his  memories 
of  the  '  old-fashioned  winter  '  in  question.  He  im- 
mediately concludes  that  the  climate  is  changing  or 
has  changed.  Similar  processes  occur  in  all  cases 
where  the  '  The  good  old  times,'  the  '  young  people 
as  they  once  were,'  and  other  facts  of  the  past,  are 
praised  on  the  basis  of  established  memory  habits. ' '  * 
In  much  the  same  way  a  person  who  writes  his  auto- 
biography is  apt  to  distort  the  facts.  He  does  not 
remember  everything,  and  he  has  unintentionally  ac- 
customed himself  to  think  of  his  conduct  and  of  his 
motives  in  a  certain  stereotyped  way.  He  has  de- 
*  Roycc,  Outlines  of  Psychology,  pp.  239-241. 


OBSERVATION  AND  MEMORY  207 

veloped  a  certain  habit  or  attitude,  and  this  habit 
is  pretty  sure  to  be  more  complimentary  to  the  normal 
individual  than  is  warranted  by  the  facts.  The  rea- 
son is  that  we  instinctively  shrink  from  those  recol- 
lections which  are  discreditable  in  any  way  to  our- 
selves. Consequently  we  are  more  upright  and  noble 
and  admirable  to  ourselves  than  to  any  one  else;  and 
to  see  ourselves  as  others  see  us,  is  a  gift  which  some 
power  other  than  ourselves  must  give  us,  if  we  are 
to  possess  it  at  all. 

The  principle  is  readily  applied  in  other  directions. 
To  a  person  who  is  credulous  in  regard  to  super- 
natural powers,  the  habits  of  mind  that  he  gradually 
acquires  tend  to  color  his  past  experiences  so  as  to 
make  them  seem  totally  different  from  what  they 
actually  were.  Imaginary  experiences  are  probably 
first  suggested  and  finally  become  incorporated.  "  It 
happened  once  to  the  writer  to  hear  a  most  scrupu- 
lously conscientious  friend  narrate  an  incident  of 
table-turning,  to  which  she  appended  an  assurance 
that  the  table  rapped  when  nobody  was  within  a  yard 
of  it.  The  writer  being  confounded  by  this  latter 
fact,  the  lady,  though  fully  satisfied  of  the  accuracy 
of  her  statement,  promised  to  look  at  a  note  she  had 
made  ten  years  previously  of  the  transaction.  The 
note  was  examined,  and  was  found  to  contain  the 
distinct  statement  that  the  table  rapped  when  the 
hands  of  six  persons  rested  on  it!  The  lady's  memory 
as  to  all  other  points  proved  to  be  strictly  correct; 
and  in  this  point  she  had  erred  in  entire  good 
faith."* 

It  seems  likely  that  in  this  instance  the  rapping  of 
*  Quoted  by  Carpenter,  Mental  Physiology,  p.  457. 


20S  AN  OUTLINE  OF  LOGIC 

the  table  was  habitually  regarded  as  an  event  outside 
the  domain  of  natural  law.  This  being  the  most 
interesting  feature  of  the  situation,  the  fact  that  the 
hands  were  on  the  table  would  naturally  be  ignored, 
since  it  tends  to  detract  from  the  appearance  of 
mystery.  In  the  end  the  occurrence  would  then  be 
remembered  without  these  details,  and  be  misrepre- 
sented in  the  way  just  described. 

The  Problem  Involved. — As  previously  indicated, 
the  recognition  that  observation  and  memory  are  sub- 
ject to  error  seems  to  make  inference  impossible.    As 
long  as  we  assume  that  our  data  are  absolutely  re- 
liable, we  have  solid  ground  upon  which  to  stand. 
But  if  the  data  furnished  through  observation  and 
memory  are  not  reliable,  what  matters  it  that  our 
inferences  about  these  data  are  drawn  in  accordance 
with  logical  requirements?     Incorrect  premises  may 
give  correct  conclusions,  but  if  they  do,  it  is  a  matter 
of  mere  chance.    Since  it  must  be  admitted  that  the 
contents  of  observation  and  memory  are  largely  con- 
structions of  our  own,  how  are  we  ever  to  find  out 
whether  these  constructions  are  correct  or  not?     If 
we  appeal  from  one  sense-experience  to  other  sense- 
experiences,  we  seem  to  overlook  the  fact  that  these 
other  sense-experiences  are  themselves  in  need  of  veri- 
fication.    Every  experience  points  beyond  itself  for 
its  proof.    No  experience  is  able  to  guarantee  its  own 
truth  absolutely.     We  wish  to  find  something  that 
is  indubitably  true,   in  order  that  we  may  have  a 
starting-point  for  inference.    But  each  experience  de- 
clares its  own  insufficiency;  and  our  quest  becomes 
like  that  of  the  child  which  set  out  to  find  the  pot 
of  gold  at  the  foot  of  the  rainbow. 


OBSERVATION  AND  MEMORY  209 

The  Solution  of  the  Problem. — The  problem, 
how  inference  gets  a  start,  which  may  appear  so 
puzzling  to  reflection,  is  one  that  does  not  even  exist 
for  unreflective  thinking  and  acting.  Practical  life 
spends  no  time  in  trying  to  unravel  the  knot,  but 
cuts  it  through,  without  even  realizing  that  the  knot 
was  there  to  be  cut.  It  does  not  attempt  to  argue 
and  prove;  it  simply  takes  for  granted.  The  solid 
foundation  which  we  seek  as  a  basis  for  inference 
is  acquired,  not  by  demonstration,  but  by  assumption. 
The  question  how  a  stable  basis  for  inference  is  to 
be  found,  suggests  an  order  of  procedure  which  is 
the  reverse  of  the  truth.  We  do  not  begin  life  in 
an  attitude  of  scepticism,  demanding  proof  for  every- 
thing before  we  accord  to  it  our  assent  or  belief.  If 
we  did,  intellectual  paralysis  would  be  the  inevitable 
result.  On  the  contrary,  our  natural  tendency  is 
to  take  things  at  their  face  value,  and  this  tendency 
rules  until  we  find  it  necessary,  for  theoretical  or  prac- 
tical reasons,  to  discriminate  between  reality  and  ap- 
pearances. Scepticism  is  not  the  spontaneous  re- 
action of  the  mind,  but  is  induced  by  the  hard  knocks 
which  experience  has  in  store  for  us.  "As  a  rule 
we  believe  as  much  as  we  can.  We  would  believe 
everything  if  we  could.  When  objects  are  represented 
to  us  quite  unsystematically  they  conflict  but  little 
with  each  other,  and  the  number  of  them  which  in 
this  chaotic  manner  we  can  believe  is  limitless.  The 
primitive  savage's  mind  is  a  jungle  in  which  hallu- 
cinations, dreams,  superstitions,  conceptions,  and  sen- 
sible objects  all  flourish  alongside  of  each  other,  un- 
regulated except  by  the  attention  turning  in  this  way 
or  in  that.    The  child's  mind  is  the  same.    It  is  only 


210  AN  OUTLINE  OF  LOGIC 

as  objects  become  permanent  and  their  relations  fixed 
that  discrepancies  and  contradictions  are  felt  and 
must  be  settled  in  some  stable  way. ' '  * 

Our  procedure,  then,  is  not  in  general  to  doubt 
where  we  can  and  believe  where  we  must,  but  to 
believe  where  we  can,  and  to  doubt  where  we  must. 
Here,  as  elsewhere,  the  coherence  of  facts  is  our  stand- 
ard of  truth.  Some  perceptions  are  discarded  as 
erroneous  because  they  do  not  harmonize  with  the 
rest.  These  others  are  treated  as  correct  perceptions 
until  there  is  specific  ground  for  doubt.  We  have 
here  something  analogous  to  the  principle  of  law 
that  every  man  is  presumed  to  be  innocent  until  he 
is  proved  guilty.  Experiences  like  dreams,  for  ex- 
ample, are  classified  as  erroneous,  in  spite  of  the  fact 
that  they  are  genuine  sense-experiences,  because  what 
the  dreams  reveal  cannot  be  reconciled  with  the  ex- 
periences of  our  waking  moments.  We  dream  of 
being  at  our  old  home  many  miles  away,  or  of  meet- 
ing a  friend  who  has  long  been  dead,  and  the  dream 
may  seem  as  real  as  any  other  experience  while  it 
lasts.  The  reason  why  at  a  later  time  we  reject  the 
claims  of  these  experiences  to  be  true  is  not  that  as 
experiences  they  are  different  from  other  experiences, 
but  that  we  find  it  impossible  to  admit  their  claims 
and  at  the  same  time  to  recognize  the  experiences  of 
our  waking  moments  as  true.  It  is  impossible  that 
we  should  have  been  away  during  the  night,  as  the 
dream  affirms,  unless  the  inference  of  the  next  morn- 
ing is  wrong  in  its  assertion  that  we  have  been  in 
the  room  continuously  since  the  evening  before.  One 
or  the  other  of  the  rival  claims  must  give  way.  The 
*  James,   Psychology,   Vol.   II.,   p.   299. 


OBSERVATION  AND  MEMORY  211 

claim  of  the  dream  is  accordingly  set  aside;  and 
that  of  the  waking  experience  is  allowed.  If  dreams 
were  regarded  as  true,  chaos  would  be  the  result. 
The  uniformity  and  orderliness  which  we  seek  to 
establish  would  be  violated  at  every  turn.  There 
would  be  no  standard  of  truth  that  we  could  apply. 
On  the  other  hand,  if  dreams  are  classed  as  just 
dreams,  they  introduce  no  serious  discord  into  our 
total  experiences.  They  upset  no  generalizations  or 
laws,  but  they  may  even  affirm  them,  in  so  far  as 
we  can  account  for  dreams  by  the  laws  that  control 
cerebral  activity,  and  by  the  psychological  laws  of 
association.  In  short,  if  dreams  are  relegated  to  the 
status  of  delusions,  they  fit  in  with  other  experiences 
in  such  a  manner  that  the  total  experience  gives 
promise  of  a  unified  and  consistent  whole,  whereas  the 
attempt  to  give  authority  to  dreams  would  lead  no- 
where at  all. 

For  exactly  the  same  reason  we  discredit  illusions 
such  as  the  feats  of  jugglery.  We  may  see  a  juggler 
take  things  out  of  a  hat  as  plainly  as  we  see  a  grocer 
take  sugar  from  a  barrel;  yet  we  discredit  the  one 
and  not  the  other.  The  reason  does  not  lie  in  any- 
thing that  pertains  to  the  experiences  themselves,  but 
in  their  relation  to  other  experiences.  The  grocer's 
act  is  so  in  accordance  with  common  experience  that 
we  do  not  feel  called  upon  to  question  our  observa- 
tion. The  doubt  is  unmotivated.  But  in  the  case 
of  the  jugglery  we  are  at  once  compelled  to  choose. 
Either  our  physics  is  wrong  in  its  assertion  that  water 
is  practically  incompressible,  or  our  present  observa- 
tion is  wrong  when  it  testifies  that  the  juggler  poured 
a  barrelful  or  more  of  water  from  the  hat.    The  laws 


212  AN  OUTLINE  OF  LOGIC 

of  physics  accomplish  too  much  towards  the  systemiza- 
tion  of  experience  to  be  given  up  without  a  struggle. 
So  we  set  down  the  present  experience  as  a  deception, 
in  the  hope  that  some  day  we  shall  be  able  to  assimi- 
late it  more  completely  to  the  body  of  our  other 
experiences  and  apply  to  it  the  laws  which  it  now 
appears  to  set  at  naught.  Meanwhile,  we  are  much 
better  off  with  but  one  or  two  such  outstanding  diffi- 
culties than  if  we  should  disorganize  our  whole  past 
experience  by  rejecting  the  conclusions  of  physical 
science  to  which  it  bears  witness. 

The  deliverances  of  memory  are  treated  in  exactly 
the  same  way.  As  with  perceptions,  we  regard  them 
as  presumably  true  in  the  absence  of  reasons  to  the 
contrary.  If  we  were  to  adopt  a  sceptical  attitude  at 
the  outset  and  demand  that  the  reliability  of  memory 
be  proved  to  us,  before  we  accept  its  testimony,  we 
should  never  get  a  start.  Just  as  perceptions  are 
proved  false  by  means  of  other  perceptions,  so  memory 
can  be  convicted  only  at  the  bar  of  memory.  No  one 
would  be  able  to  prove  even  his  own  name  without 
the  assistance  of  other  recollections,  whether  his  own 
or  those  of  other  persons.  If  I  happen  to  know  that 
my  memory  is  unreliable,  it  is  because  I  remember 
how  wayward  it  has  been  on  previous  occasions;  or 
if  the  case  be  exceptionally  bad,  my  knowledge  is 
based  on  the  statements  of  friends,  who,  on  their 
part,  simply  report  the  things  which  their  respective 
memories  attest.  Recollections  that  fit  in  with  our 
experience,  i.e.,  with  our  memories  and  perceptions 
and  the  inferences  based  thereon,  are  thereby  proved 
to  be  true,  while  those  which  conflict  are  set  aside 
as  delusions.     That  perception  and  memory  are  com- 


OBSERVATION  AND  MEMORY  213 

petent  to  give  us  truth,  is  a  basal  assumption  or 
postulate  in  our  conscious  life.  Hence  each  indi- 
vidual perception  or  recollection,  regarded  by  itself, 
carries  with  it  a  certain  measure  of  probability.  In 
case  of  doubt  the  final  court  of  appeal  is  the  con- 
vergence of  evidence. 

Observation  and  Explanation. — It  has  already 
been  said  that  the  term  '  observation  '  is  loosely  ap- 
plied. It  includes  not  only  actual  sense-impressions, 
but  in  general  all  objects  and  events  that  are  easily 
understood.  That  is,  the  term  covers  both  the  sense- 
qualities  apart  from  the  inferential  element,  and  the 
sense-qualities  plus  the  inference.  "Whenever  the  in- 
terpretation of  a  perception  suggests  itself  spon- 
taneously and  immediately,  we  are  inclined  to  regard 
the  whole  as  a  fact  of  observation.  Thus,  as  we  com- 
monly say,  we  observe  that  the  man  is  excited  or 
that  the  horse  is  frightened.  "We  are  at  no  loss  to 
interpret  our  perceptions,  nor  are  errors  in  such 
interpretation  relatively  frequent.  Hence  perception 
and  interpretation  are  fused  in  our  minds  and  both 
seem  to  be  immediately  given.  If  the  interpretation 
that  we  desire  is  not  forthcoming  in  this  immediate 
fashion,  but  requires  an  effort,  we  tend  to  set  the 
interpretation  over  against  the  perception  and  call 
it  an  explanation.  To  interpret  is  to  relate  to  other 
facts.  Both  observation  and  explanation,  therefore, 
are  forms  of  interpretation.  That  sparks  explode 
powder  is  usually  regarded  as  a  matter  of  observa- 
tion, because  we  unhesitatingly  assume  a  causal  con- 
nection between  the  two  events,  although  the  causal 
connection  is  not  a  matter  of  sense-perception.  The 
explosion  is  said,  on  the  other  hand,  to  be  explained 


21  i  AN  OUTLINE  OF  LOGIC 

when  the  chemical  process  involved  in  the  explosion 
is  made  clear.  The  explanation  relates  the  fact  in 
question  to  a  still  wider  range  of  facts ;  and  the  more 
completely  this  is  done,  the  more  complete  is  our 
explanation.  Observation  in  the  wider  sense,  therefore, 
is  a  matter  of  theory,  in  the  same  sense  as  the  most 
complex  explanation ;  and  incorrect  observation  means 
a  failure  to  analyze  out  all  the  important  elements  of 
the  situation  (c/.  p.  141).  To  conclude,  then,  the 
term  observation,  in  the  narrower  sense,  applies  only 
to  the  awareness  of  qualities  presented  to  the  senses. 
If,  however,  the  term  be  taken  in  the  wider  and  more 
usual  sense,  observation  differs  from  explanation  only 
in  degree,  and  the  line  between  the  two  cannot  be 
closely  drawn. 

A  word  of  warning  may  be  added.  As  was  sug- 
gested just  now,  explanation  advances  in  proportion 
as  the  fact  to  be  explained  is  related  to  other  facts. 
Thus  lightning  is  explained  when  it  is  found  to  be 
a  case  of  electricity.  The  demand  for  explanation, 
therefore,  is  properly  met,  if  we  are  able  to  subsume 
the  given  case  under  a  general  law,  i.e.,  group  it 
with  a  class  of  cases,  for  this  enables  us  to  apply 
what  we  already  know  to  the  case  in  hand.  To  classify 
a  new  case  with  other  cases,  then,  constitutes  ex- 
planation, provided  that  by  so  doing  we  are  enabled 
to  see  the  new  case  in  new  relations.  But  unless 
new  knowledge  is  gained,  we  have  merely  given  a 
name  to  the  new  fact;  and  there  is  danger  that 
the  naming  be  mistaken  for  explanation.  "At  a 
surgical  operation  I  once  heard  a  bystander  ask  a 
doctor  why  the  patient  breathed  so  deeply.  '  Because 
ether  is  a  respiratory  stimulant, '  the  doctor  answered. 


OBSERVATION  AND  MEMORY  215 

1  Ah !  '  said  the  questioner,  as  if  that  were  a  good 
explanation.  But  this  is  like  saying  that  cyanide  of 
potassium  kills  because  it  is  a  '  poison,'  or  that  it 
is  so  cold  to-night  because  it  is  c  winter,'  or  that  we 
have  five  fingers  because  we  are  '  pentadactyls. '  "  * 

*  James,  Pragmatism,  p.  263. 


CHAPTER  XIV 
THE  NATURE  OF  REASONING 

After  the  preceding  survey  of  the  processes  by 
which  knowledge  is  built  up,  we  are  in  a  position  to 
inquire  a  little  more  closely  into  the  nature  of 
reasoning  or  inference.  It  has  been  shown  that  the 
recognition  of  resemblance  and  difference  plays  a 
leading  part  in  the  extension  of  knowledge.  Since 
experience  alone  can  guide  our  reasoning,  it  is  nec- 
essary in  every  situation  to  find  a  point  of  contact 
with  other  experiences.  Through  comparison  with 
other  experiences  we  discover  the  important  likeness 
or  difference,  which  is  then,  by  means  of  the  Methods, 
isolated  from  its  concomitants  and  associated  with 
the  attribute  which  it  implies  or  to  which  it  is  related. 

The  Definition  of  Reasoning — We  may,  there- 
fore, adopt  the  definition  of  reasoning  that  is  offered 
by  Professor  James,  who  says  that  reasoning  is  "  the 
substitution  of  parts  and  their  implications  or  con- 
sequences for  wholes.1"  *  The  part  that  is  substituted 
for  the  whole  is  the  point  of  resemblance  or  of  differ- 
ence. This  attribute  or  circumstance  is  then  treated 
as  a  ground  for  asserting  the  conclusion  of  the  infer- 
ence, i.e.,  the  conclusion  is  regarded  as  its  implication 
or  consequence.  If  we  say  that  Socrates  is  a  man 
and  therefore  mortal,  we  substitute  for  the  complex 

*  Psychology,   Vol.    II.,   p.    330. 
216 


THE  NATURE  OF  REASONING  217 

whole,  '  Socrates,'  the  attribute  '  man,'  and  then 
pass  on  to  the  conclusion  '  mortal,'  because  '  mortal ' 
is  regarded  as  implied  in  '  man.'  Similarly  when  we 
infer  to  a  generalization,  we  reason  that  A,  B,  and 
C  are  men  (point  of  resemblance)  and  mortal,  there- 
fore all  men  are  mortal,  or  the  attribute  '  man  ' 
implies  the  attribute  '  mortal.'  Here  again  we  sub- 
stitute for  the  several  instances  an  attribute  that  is 
part  of  the  whole  and  associate  with  that  part  the  at- 
tribute which  we  regard  as  its  implication. 

This  substitution  is  equally  fundamental  though 
somewhat  less  obvious  in  inferences  with  a  negative 
conclusion.    Take  the  syllogism: 

All  voters  are  taxpayers; 
He  is  not  a  taxpayer; 
Therefore  he  is  not  a  voter. 

This  major  premise  is  equivalent  to,  {  None  who 
are  not  taxpayers  are  voters,'  this  second  proposition 
being  derivable  from  it  by  processes  of  obversion 
and  conversion.  The  point  of  resemblance,  therefore, 
is  l  not  a  taxpayer, '  which  carries  with  it  the  implica- 
tion '  not  a  voter. ' 

Logical  Necessity. —  The  characteristic  feature  of 
inference  is  that  it  involves  a  '  Therefore.'  '  A  is 
X  and  therefore  it  is  B.'  The  assertion  '  A  is  X  ' 
is  based  upon  the  awareness  of  a  resemblance:  the 
1  therefore  '  indicates  the  awareness  that  X  is  a  con- 
dition from  which  B  follows  as  a  necessary  result; 
or,  to  put  it  differently,  that  X  is  the  kind  of  fact 
which  always  involves  B.  If  A  is  X  it  must  be  B. 
This  must  be  is  known  as  logical  necessity,  to  dis- 


218  AN  OUTLINE  OF  LOGIC 

tinguish  it  from  the  necessity  that  depends  upon 
causation.  If  we  say,  for  example,  that  food  placed 
far  back  in  the  mouth  is  necessarily  swallowed  or  that 
neglected  children  necessarily  have  bad  manners,  the 
necessity  which  is  meant  is  not  of  a  logical,  but  of 
a  causal  character.  The  statement  affirms  that  under 
certain  conditions  certain  consequences  invariably  re- 
sult. The  assertion — to  take  another  illustration — 
that  unsupported  objects  necessarily  fall,  need  mean 
nothing  further  than  that  the  connection  between 
body  and  falling  is  not  accidental,  but  involves  a  rule 
of  sequence.  The  connection  is  operative  whether  we 
happen  to  be  aware  of  the  events  or  not;  whereas 
logical  necessity  exists  only  for  consciousness.  More- 
over, inference  may  proceed  from  effect  to  cause  as 
readily  as  from  cause  to  effect,  or  may  deal  with  facts 
independently  of  causation,  as  in  mathematics.  By 
causal  necessity,  then,  is  meant  in  logic  merely  a 
certain  invariable  rule  of  sequence;  by  logical 
necessity  is  meant  that  we  can  avoid  self-contradiction 
only  by  the  acceptance  of  a  certain  inference  as 
valid. 

Judgment  and  Inference. — We  have  seen  pre- 
viously that  the  various  forms  of  inference  are  marked 
off  by  no  hard  and  fast  lines.  Analogy,  generaliza- 
tion, and  circumstantial  evidence  blend  into  each  other 
as  day  blends  into  night.  We  must  now  observe  that 
it  is  no  easy  matter  to  determine  where  inference 
begins.  If  we  compare  judgment  and  inference,  we 
find  that  the  former  is  an  unsupported  assertion, 
such  as  'A  is  B  ' ;  whereas  inference  involves  the 
characteristic  feature  of  necessity,  typified  in  '  A  is 
X  and  therefore  B.'    At  their  extremes  the  two  are 


THE  NATURE  OF  REASONING  219 

easily  distinguished,  but  the  distance  between  the 
extremes  is  occupied  by  intermediate  forms,  which 
are  neither  judgments  pure  and  simple,  nor  yet  ex- 
plicit inferences,  since  they  do  not  contain  a  clear 
consciousness  of  the  grounds  upon  which  they  rest. 

The  element  of  necessity,  which  distinguishes  in- 
ference, is  incidental,  as  was  pointed  out,  to  the  sub- 
stitution of  the  part  and  its  implication  for  the  whole. 
When  the  part  is  discovered  within  the  whole,  we 
realize  that  the  implication  must  likewise  belong  to 
the  whole,  because  the  part  is  known  to  carry  with 
it  this  implication.  But  in  the  simpler  forms  of 
assertion  these  successive  steps  from  whole  to  part 
and  from  part  to  implication  do  not  appear.  There 
is  no  clear  distinction  between  whole  and  part,  with 
the  result  that  the  implication  is  associated  with  the 
whole  directly,  and  not  by  the  more  roundabout  way. 
The  part  which  constitutes  the  middle  term,  or  the 
connecting  link,  between  the  whole  and  the  implica- 
tion, tends  to  drop  out  of  sight.  Instead,  therefore, 
of  A  is  X  and  X  is  B  we  have  simply  A  is  B,  which 
is  a  simple  judgment,  the  element  of  necessity  having 
disappeared. 

As  an  illustration,  let  us  take  the  perceptive  judg- 
ment, '  This  is  a  tree.'  The  subject  term  of  this 
proposition  points  out  a  complex  sense-experience, 
which  is  described  or  classified  by  the  predicate  term 
as  '  tree.'  This  proposition  is  commonly  regarded  as 
a  statement  of  observation,  but  it  goes  far  beyond 
what  is  given  in  the  perception.  What  we  get  through 
perception  is  mainly  certain  colors  and  shapes.  The 
assertion  that  the  object  is  a  tree  implies  vastly  more 
than  this.    It  asserts  attributes  not  perceived  at  the 


220  AN  OUTLINE  OF  LOGIC 

moment,  such  as  that  the  tree  is  something  which 
grows,  that  it  may  be  destroyed  by  being  cut  down, 
that  it  furnishes  protection  against  wind  and  sun, 
and  so  on.  It  seems,  therefore,  that  in  the  actual 
sensory  experience  we  recognize  a  point  of  resem- 
blance to  other  experiences,  and  on  the  strength  of 
this  resemblance  we  assert  these  unperceived  attri- 
butes. This  is  the  same  as  saying  that  for  the  whole 
we  substitute  the  part,  viz.,  those  attributes  wherein 
the  present  experience  resembles  other  experiences, 
and  that  we  then  assert  the  unperceived  attributes  as 
the  implication  of  this  part.  But  as  a  matter  of  fact 
we  do  not  take  these  successive  steps.  "Whole  and 
part  are  not  distinguished;  they  are  telescoped,  so  to 
speak,  and  instead  of  an  inference  we  have  the  simple 
judgment,  '  this  is  a  tree.' 

In  the  case  of  a  judgment  like  '  this  is  green,'  if 
the  judgment  is  taken  to  apply  only  to  what  is  per- 
ceived, the  analysis  is  more  difficult,  but  the  principle 
is  precisely  the  same.  The  judgment  classifies  this 
particular  quality  as  an  instance  of  green.  The  green 
that  is  affirmed  of  '  this  '  is  not  something  that  belongs 
to  this  instance  alone,  is  not  merely  this  particular 
shade  of  green,  but  is  something  that  is  shared  by 
others.  Even  in  this  judgment,  therefore,  we  do  not 
confine  ourselves  wholly  to  what  is  before  us,  but  we 
imply  a  reference  to  other  cases  of  green.  The  mo- 
ment we  say  anything  about  an  experience  we  are 
already  beyond  it.  The  judgment,  '  this  is  green,'  is 
equivalent  to  '  this  resembles  other  instances  of 
green.'  It  is  true  that  we  may  not  happen  to  think 
of  other  instances.  But  the  fact  that  we  classify  this 
sense-quality  shows  that  we  recognize  it,  and  such 


THE  NATURE  OF  REASONING  221 

recognition,  as  we  have  seen  before,  is  an  awareness 
of  resemblance.  Here  again,  therefore,  we  can  break 
up  the  judgment  into  three  stages: 

This    sense-perception    (S) — this    color-quality     (M)  — 
green  (i.e.,  resemblance  to  other  greens)   (P). 

The  sense-perception  as  a  whole  has  certain  features 
which  are  ignored,  such  as  the  outline  of  the  color 
and  its  position  before  us.  For  the  whole  perception 
we  substitute  the  part,  viz.,  the  color-quality,  and 
this  carries  with  it  the  implication  of  resemblance  to 
other  instances  of  green.  But  in  this  case,  as  in 
the  preceding,  these  three  stages  do  not  succeed  each 
other.  The  second  stage  is  suppressed,  and  we  have 
simply,  '  this  is  green.' 

In  this  connection  we  may  notice  again  a  fact  which 
was  brought  out  in  connection  with  the  discussion 
of  class  names,  viz.,  the  tendency  to  substitute  words 
for  clear  ideas.  We  have  just  seen  that  even  a  judg- 
ment like,  '  This  is  green,'  is  a  rather  complex  affair, 
if  we  give  consideration  to  its  implications.  But  in- 
stead of  explicit  analysis,  we  tend  to  content  our- 
selves with  felt  resemblances,  in  which  the  distinction 
between  whole  and  part  is  submerged.  We  recognize 
the  quality  and  feel  the  appropriateness  of  the  name, 
and  that  is  all.  Now  if  two  things  have  the  same 
name,  our  attention  is  explicitly  called  to  the  simi- 
larity between  the  things,  to  the  neglect  of  the  differ- 
ences. Or  we  may  say  that  the  resemblances  are 
emphasized  at  the  expense  of  the  differences.  Our 
tendency  to  accept  resemblances  without  clear-cut 
analysis,  i.e.,  without  definite  contrast  between  like- 


222  AN  OUTLINE  OF  LOGIC 

ness  and  difference,  is  thus  reinforced  by  language, 
■with  the  result  that  the  latter  becomes  a  treacherous 
instrument,  as  our  study  of  ambiguity  has  shown. 

From  the  foregoing  discussion  it  appears  that  judg- 
ment partakes  of  the  nature  of  inference  in  propor- 
tion as  the  connecting  link  between  A  and  B  comes 
into  view;  for  this  connecting  link  brings  out  the 
generalization,  X  is  B.  Wherever  we  find  X,  under 
the  proper  conditions,  we  may  treat  it  as  a  datum 
that  involves  or  implies  B.  Judgment,  therefore,  ac- 
cording to  this  view,  "  is  merely  the  lower  limit  of 
inference,  where  datum  and  result  are  frankly  fused 
in  one  statement.  The  logic  of  both  processes  is  the 
same.  In  both,  thought  begins  with  A  and  elaborates 
it  into  B ;  but  in  the  one  it  simply  asserts  B  without 
explaining  whether  it  is  datum  or  result,  and  so  it 
is  judgment,  a  simple  assertion  that  is  not  at  the 
pains  to  justify  itself;  in  the  other  it  makes  this 
distinction:  its  datum  is  specified,  and  becomes  the 
premise,  and  its  result  is  marked  off  and  figures  as 
conclusion.  And  between  these  clear  cases  we  may 
in  concrete  thought  have  all  kinds  of  intermediate 
stages ;  and  it  is,  as  has  been  rightly  said,  '  the  merest 
chance  '  whether  we  adopt  the  more  or  the  less  ex- 
plicit form.  '  He  must  be  a  fool,'  is  an  undoubted 
judgment.  '  A  man  who  acts  like  that  is  clearly  a 
fool,'  is  in  judgment  form,  but  the  distinction  of 
ground  and  consequent  is  already  made.  Turn  them 
into  separate  judgments  with  a  connecting  particle, 
'  he  did  this  or  that  '  (premise),  '  so  he  must  be  a 
fool  '  (conclusion),  and  we  have  formal  inference."  * 

From  this  point  of  view  judgments  are  rudimentary 
♦Hobhouse,  The  Theory  of  Knowledge,  pp.  219-220. 


THE  NATURE  OF  REASONING  223 

forms  of  inference.  The  differentiating  feature  is  the 
element  of  logical  necessity.  If,  therefore,  our  defini- 
tion of  reasoning  is  to  exclude  simple  judgments,  we 
must  take  it  to  mean  that  in  the  substitution  of  part 
and  implication  for  whole,  the  distinction  between 
part  and  whole  must  be  maintained. 

The  Reasoning  of  Animals. — This  character  of 
judgments  explains  why  the  actual  boundaries  of 
inference  are  so  hard  to  determine.  The  connecting 
link  between  subject  and  predicate  may  be  present 
in  any  degree  of  explicitness.  To  ask  where  infer- 
ence starts  is  much  like  asking  where  night  leaves 
off  and  day  begins.  The  perennial  discussions  about 
the  reasoning  of  animals  bear  out  this  point.  In 
spite  of  much  argument,  the  question  seems  as  far 
from  solution  as  ever;  which  suggests  that  there  is 
more  need  of  definition  than  of  argument.  That 
reasoning  is  a  vague  term  which  easily  becomes  am- 
biguous seems  usually  not  to  be  suspected  at  all.  We 
find  in  fact  that  the  mental  processes  of  the  higher 
animals  are  to  all  appearances  the  same  in  kind  as 
ours;  so  that  if  we  wish  to  contrast  the  reasoning 
of  men  with  the  reasoning  of  brutes,  we  must  look 
for  a  difference  of  degree  and  not  of  kind. 

That  animals  are  capable  in  some  sense  of  sub- 
stituting the  part  and  its  implication  for  the  whole 
does  not  admit  of  doubt.  Some  dogs,  for  example, 
are  quick  to  recognize  tramps  and  to  adopt  a  hostile 
attitude  towards  them.  It  is  clear  that  there  is  some 
generic  mark  or  point  of  resemblance  to  which  the 
dogs  react,  while  other  attributes  of  the  persons  classi- 
fied as  tramps  are  ignored.  Made  explicit  the  mental 
process  would  be  something  as  follows: 


224  AN  OUTLINE  OF  LOGIC 

This  person  (S)— Tramp   (M)— Objectionable  (P). 

The  important  question,  however,  in  this  connection 
is  to  what  extent  animals  are  capable  of  making  this 
relation  explicit  to  themselves.  This  point  it  is  diffi- 
cult to  determine.  The  fact  that  a  person  or  an 
animal  responds  to  a  certain  attribute  of  an  object 
is  no  evidence  that  this  attribute  is  clearly  marked 
off  from  others  with  which  it  is  conjoined.  As  we 
cross  a  crowded  street  we  '  instinctively  '  avoid  colli- 
sions with  street-cars  and  automobiles,  i.e.,  we  react 
to  a  certain  attribute  which  they  possess  in  common, 
but  we  may  never  take  the  trouble  to  ascertain  just 
what  that  attribute  may  be.  In  explicit  form  the 
inference  would  be: 

This  object  (S)— Large  Approaching  Body  (M)— To  Be 
Avoided  (P). 

In  a  rudimentary  form  this  inferential  process  does 
indeed  occur  on  such  occasions,  but,  as  a  rule,  only 
in  rudimentary  form.  Much  of  our  reasoning  is  of 
this  imperfect  kind.  And  it  may  be  that  animals 
never  get  beyond  this  point.  That  such  is  the  case 
is  the  consensus  of  opinion  among  psychologists.  Ani- 
mals apparently  do  not  treat  the  part  explicitly  as 
a  condition  for  the  result,  but  vaguely  join  the  whole 
to  the  result,  without  a  clear  awareness  of  the  func- 
tion performed  by  the  part  or  connecting  link.  As 
a  well-known  psychologist  states  it,  animals  do  not 
think  the  therefore* 

To  consider  the  evidence  upon  which  this  opinion 

*  Lloyd  Morgan,  Introduction  to  Comparative  Psychology, 
Chapter  XVI.,  p.  287. 


THE  NATURE  OF  REASONING  225 

is  based  would  take  us  too  far  afield.  For  our  present 
purposes  its  correctness  or  incorrectness  is  a  matter 
of  no  special  importance.  If  we  assume  that  it  is 
correct,  the  superiority  of  the  human  mind  lies  in 
the  fact  that  it  is  able  to  set  free  or  detach  completely 
the  point  of  resemblance  or  of  difference  from  its 
different  contexts  or  settings.  This  is  the  process 
which  lays  the  foundation  of  science.  Animals  are 
poorer  reasoners,  because  they  are  less  able  to  draw  a 
sharp  line  between  the  whole  and  the  attribute  that 
belongs  to  the  whole,  i.e.,  they  do  not  form  clearly  de- 
fined ideas,  but  tend  to  be  guided  wholly  by  undefined 
resemblance  and  difference.  Human  beings  can  in 
many  instances  form  clearly  defined  ideas,  although 
in  fact  much  of  our  thinking  resembles  that  of  the 
brutes. 

Why  Some  Persons  Reason  Better  than  Others. — 
The  difference  between  men  and  brutes,  in  the  matter 
of  reasoning,  gives  us  the  clue  to  the  explanation  of 
the  differences  in  reasoning  ability  among  men.  It 
was  pointed  out  before  that  points  of  resemblance  or 
of  difference  may  be  '  felt  '  instead  of  being  clearly 
discriminated.  We  may  feel  that  a  certain  proposed 
course  of  conduct  is  right  or  that  a  proposed  business 
venture  will  succeed,  although  we  are  unable  to  give 
reasons  with  any  degree  of  adequateness.  Or  we  may 
feel  that  the  proposed  conduct  is  not  right,  or  that 
the  business  venture  will  fail,  again  without  being 
able  to  justify  our  opinion.  The  propositions  may 
seem  plausible,  i.e.,  they  may  resemble  others  that 
are  unobjectionable,  yet  we  feel  that  there  is  an  im- 
portant difference.  This  has  been  discussed  before 
and  needs  no  further  elaboration.    It  should  be  noted, 


226  AN  OUTLINE  OF  LOGIC 

however,  that  men  differ  enormously  in  their  sensitive- 
ness to  resemblances  and  differences.  This  sensitive- 
ness, moreover,  may  endow  a  man  with  practical 
wisdom,  even  though  he  be  unlearned,  and  the  lack 
of  it  makes  possible  the  learned  fool.  However  much 
we  may  know,  we  can  never  walk  by  the  light  of 
clearly  denned  knowledge  alone.  It  may  be  added 
that  this  sensitiveness  to  undefined  resemblances  and 
differences  may  operate  with  certain  materials  or  in 
certain  fields  and  be  conspicuously  absent  elsewhere. 
Every  expert  acquires  a  certain  measure  of  it  in  his 
own  field,  but  he  may  be  curiously  inefficient  in  others. 
The  man  of  practical  wisdom  is  not  necessarily  a 
good  student,  if  given  the  opportunity;  his  range  of 
interests  may  be  too  limited.  And  some  of  the  mathe- 
matical prodigies  who  have  attracted  world-wide  at- 
tention have  been  very  ordinary,  or  worse,  in  other 
matters. 

Leaving  aside  the  reasoning  that  is  based  upon 
the  awareness  of  undefined  attributes,  we  may  say 
that  the  test  of  reasoning  lies  in  the  power  to  form 
clear  and  distinct  ideas,  i.e.,  in  the  power  to  break 
up  our  subject-matter  into  its  different  parts  or  ele- 
ments. By  a  clear  and  distinct  idea  is  meant  an  idea 
that  has  a  well-understood  content  and  that  is  marked 
off  definitely  from  everything  else.  Two  reasons  may 
be  given  why,  with  the  same  amount  of  effort  and 
attention,  some  persons  analyze  more  successfully  than 
others. 

One  reason  is  that  some  persons  possess  more  in- 
formation than  others.  Attributes  that  have  been 
singled  out  previously  are  recognized  more  easily  than 
others,  because  the  association  established  in  previous 


THE  NATURE  OF  REASONING  227 

experience  come  to  our  aid  in  directing  our  attention 
and  in  giving  greater  prominence  to  details  which 
might  otherwise  be  overlooked.  Resemblances  and 
differences  are  thus  detected  with  greater  facility. 
This  is  the  reason  why  a  machinist  is  at  home  in  a 
shop  which  to  another  person  is  a  bewildering  con- 
fusion of  wheels  and  belts  and  other  apparatus,  or 
why  a  physician  notices  symptoms  that  are  not  per- 
ceived by  a  layman. 

A  second  reason  is  that  some  persons  have  much 
more  native  ability  than  others  in  detecting  resem- 
blances and  differences.  According  to  modern  psy- 
chology, this  difference  must  ultimately  be  accounted 
for  in  terms  of  brain  processes.  When  similar  things 
occur  to  consciousness  at  the  same  time  in  different 
contexts  (resemblance),  or  when  different  things  occur 
in  similar  contexts  (difference),  we  tend  to  take  notice 
of  them.  Thus  we  can  hardly  fail  to  notice  the  like- 
ness between  a  doll  and  a  baby  (resemblance  amid 
difference),  or  the  difference  between  a  white  and  a 
black  horse    (difference  amid  resemblance). 

Illustrations  of  more  obscure  resemblance  and  dif- 
ference, in  the  detection  of  which  the  differences  in 
native  ability  appear,  have  been  supplied  in  the  fore- 
going discussions.  People  vary  greatly  in  the  power 
of  seeing  analogies,  and  also  in  the  power  of  criti- 
cizing analogies,  i.e.,  in  discovering  important  differ- 
ences. Analogy,  as  we  have  seen,  is  a  form  of  re- 
semblance; whereas  the  criticism  of  analogy  and  the 
application  of  the  Method  of  Difference  concern  them- 
selves more  particularly  with  differences.  A  classic 
instance  of  analogy  is  furnished  in  Newton's  discovery 
of  the  law  of  gravitation.     According  to  the  well- 


228  AN  OUTLINE  OF  LOGIC 

known  story,  a  falling  apple  suggested  to  Newton  a 
resemblance  between  its  motion  and  the  motion  of 
the  moon.  "Whether  or  not  the  story  is  true,  Newton 
at  all  events  discovered  a  resemblance  between  the 
motion  of  the  moon  and  the  motion  of  falling  bodies. 
The  resemblance  is  too  slight  to  suggest  itself  readily ; 
for  the  motion  of  a  falling  body  does  not  resemble  the 
actual  motion  of  the  moon,  but  merely  one  of  the 
components  into  which  the  motion  of  the  moon  may 
be  resolved.  The  two  components  or  tendencies  of 
a  circular  motion  are  a  tendency  towards  the  center 
of  the  circle,  and  a  tendency  at  every  point  on  the 
circle  to  go  off  on  a  tangent.  This  is  exemplified  by 
swinging  in  a  circle  a  small  body  attached  to  a  string. 
The  pull  exerted  by  the  hand  on  the  string  is  one 
component,  the  pull  in  the  direction  of  tangential 
motion — the  motion  which  occurs  whenever  the  string 
is  released — is  the  other;  the  resultant  of  the  two 
is  the  circle.  The  resemblance  noticed  by  Newton 
is  between  the  motion  of  the  falling  body  towards 
the  center  of  the  earth  and  the  tendency  of  the  moon 
towards  the  center  of  the  circle  that  it  describes  about 
the  earth,  i.e.,  towards  the  earth  itself.  This  resem- 
blance furnished  a  starting-point  for  the  discovery 
of  further  resemblances,  which  collectively  constituted 
proof  by  circumstantial  evidence. 

The  Development  of  Inference. — A  study  of  in- 
ference seems  to  show  that  inference,  judgment,  and 
concept  develop  together.  There  is  reason  to  think 
that  none  of  them  can  be  found  in  clear-cut  form 
in  the  primitive  or  undeveloped  mind.  Judgment  and 
inference,  as  we  have  seen,  tend  to  fuse.  In  the  lower 
forms  of  thinking,  the  inferential  processes  are  not 


THE  NATURE  OF  REASONING  229 

unequivocally  such,  because  a  clear  distinction  of 
whole  and  part,  and  with  it  a  clear  awareness  of 
logical  necessity,  are  absent.  This  implies  a  like 
absence  of  clear  and  distinct  ideas;  since  the  reason 
that  the  inference  is  inexplicit  is  due  to  the  fact  that 
the  point  of  resemblance  or  of  difference  is  not  de- 
fined, which  tends  to  leave  the  distinction  between 
whole  and  part  obscure.  And  it  seems  clear  that 
most,  if  not  all,  of  the  simple  judgments  with  which 
we  are  familiar  in  adult  life  are  simpler  than  they 
were  at  the  outset.  The  judgment,  '  this  is  a  tree,' 
is  simple  because  we  have  become  so  accustomed  to 
the  sight  of  trees  that  the  judgment  has  become  more 
or  less  automatic.  If  we  imagine  ourselves  in  doubt 
whether  a  given  object  is  a  tree,  we  find  that  the 
distinction  between  whole  and  part  tends  to  be  re- 
instated. Our  mental  process  is  then  something  as 
follows:  This  object  has  an  upright  trunk  with  a 
spreading  top  and  makes  a  rustling  noise  in  the 
wind;  therefore  it  is  a  tree.  Some  such  process  as 
this  occurs  whenever  we  are  in  doubt;  but  as  we 
become  habituated  to  objects,  the  process  is  no  longer 
necessary,  and  the  simplification  of  the  process 
through  the  telescoping  of  part  and  whole  is  an  in- 
evitable result. 

It  seems,  then,  that  thinking  takes  as  its  starting- 
point  a  form  of  consciousness  which  has  within  it 
the  promise  and  potency  of  concept,  judgment,  and 
inference,  but  which  is  none  of  these  in  fully  de- 
veloped form.  Growth  takes  place,  not  through  the 
mere  addition  of  new  parts,  but  through  the  develop- 
ment of  what  is  present  in  germ.  The  process  has 
been  likened  to  that  of  growth  within  a  living  organ- 


230  AN  OUTLINE  OF  LOGIC 

ism,  because  it  is  a  process  that  involves  a  differentia- 
tion of  structure  through  an  inner  growth. 

This  conclusion  may  be  reinforced  by  the  examina- 
tion of  a  conflicting  view.  It  is  held  by  some  logi- 
cians *  that  knowledge  begins  with  the  formation  of 
concepts;  that  these  are  then  combined  into  judg- 
ments, after  which  the  judgments  are  combined  into 
inferences.  A  judgment,  according  to  this  theory, 
consists  of  two  ideas,  corresponding  respectively  to 
the  subject-term  and  the  predicate-term.  Judgments 
are  formed  by  comparing  these  two  ideas,  to  determine 
whether  they  '  agree  '  or  '  disagree.'  To  say,  for 
example,  '  the  sky  is  blue,'  means  that  we  compare 
the  concept  '  sky  '  with  the  concept  '  blue  '  and  find 
that  the  latter  can  be  asserted  of  the  former.  A 
negative  judgment,  such  as,  '  the  sky  is  not  cloudy,' 
means  that  there  is  a  lack  of  agreement.  Inferences, 
finally,  are  formed  by  bringing  together  two  judg- 
ments in  the  relation  of  major  and  minor  premise. 
Reasoning,  therefore,  is  an  orderly  progression  from 
the  simple  to  the  complex;  concept,  judgment,  and 
inference  do  not  develop  concomitantly,  but  in  suc- 
cession; and  inference  is  merely  the  final  result 
of  a  somewhat  mechanical  addition  of  part  to 
part. 

This  view  has  the  merit  of  simplicity,  but  it  can 
hardly  be  squared  with  the  facts.  Thus  there  are 
certain  judgments,  such  as  '  it  rains,' '  it  is  lightening,' 
'  it  is  cold,'  etc.,  which  do  not  seem  to  be  formed 
by  the  joining  or  comparing  of  two  ideas.  It  seems 
more  natural  to  regard  judgments  of  this  kind  as 
belonging  to  a  more  primitive  type  of  thinking,  a  type 
*  Cf.  Jevons,  Lessons  in  Logic,  pp.  9-10. 


THE  NATURE  OF  REASONING  231 

in  which  subject  and  predicate  have  not  yet  been 
differentiated,  except  as  to  verbal  form.  In  the  case 
of  these  judgments  it  is  difficult  to  discover  the  two 
ideas  that  are  supposed  to  be  compared  with  each 
other,  or  to  detect  any  mental  process  of  comparison. 
The  same  is  true,  though  perhaps  less  obviously,  in 
'  judgments  of  existence,'  e.g.,  '  God  exists.' 

Even  in  the  more  developed  forms  of  judgment, 
moreover,  there  is  good  reason  to  think  that  the  act 
of  judging  is  something  different  from  the  comparing 
of  two  ideas.  So  far  as  the  ideas  are  concerned,  '  the 
horse  runs  '  is  the  same  as  c  the  running  horse,'  yet 
the  former  is  a  judgment,  while  the  latter  is  not. 
We  get  a  judgment  when  the  single  complex  idea, 
'  the  running  horse,'  is  asserted  to  be  a  fact,  or  is 
asserted  to  be  true  of  reality.  The  difference  between 
1  the  running  horse  '  and  '  horse  '  is  merely  a  differ- 
ence in  complexity,  the  former  being  a  single  idea 
as  well  as  the  latter.  But  we  find  in  '  the  horse  runs  ' 
the  differentiation  into  subject  and  predicate,  which 
means  that  the  judgment  does  not  merely  assert  the 
relatively  undifferentiated  idea  '  horse,'  but  dis- 
criminates an  attribute  which  characterizes  the  horse 
at  the  time  when  the  judgment  is  made.  The  char- 
acteristic feature  of  judgment,  therefore,  is  not  the 
comparison  of  two  ideas,  but  the  assertion  of  a  single 
idea  as  true  of  reality. 

The  view  which  we  have  been  criticizing  suggests 
that  concepts  antedate  judgments.  That  some  con- 
cepts precede  some  judgments  is  undoubtedly  a  fact, 
but  that  concepts  precede  all  judgments  is  a  different 
matter.  "  In  making  a  judgment  like  '  iron  is  a 
metal,'  it  is,  of  course,  necessary  to  have  the  concept 


232  AN  OUTLINE  OF  LOGIC 

'  iron  '  and  the  concept  '  metal. '  But  what  is  im- 
plied in  having  a  concept  of  anything?  Let  us  sup- 
pose that  a  person  is  making  the  above-mentioned 
judgment  for  the  first  time — that  is,  really  drawing 
a  conclusion  for  himself,  and  not  merely  repeating 
words.  He  would  begin,  we  may  say,  with  the  con- 
cept '  iron. '  But  if  this  concept  is  more  than  a  mere 
word,  if  it  really  means  anything,  it  must  have  been 
formed  by  a  number  of  judgments.  The  concept 
*  iron, '  if  it  has  any  significance  for  the  persons  using 
it,  means  a  definite  way  of  judging  about  some  sub- 
stance—that it  is  hard,  malleable,  tough,  etc.  The 
greater  the  number  of  judgments  which  the  concept 
represents,  the  more  meaning  or  significance  it  has; 
apart  from  the  judgment,  it  is  a  mere  word,  and 
not  a  thought  at  all.  .  .  .  The  concept,  then,  stands 
for  the  series  of  judgments  which  have  already  been 
made.  Language  comes  to  the  aid  of  thought,  and 
makes  it  possible  to  gather  up  such  a  set  of  judgments 
and  represent  them  by  a  single  expression — often  by 
a  single  word.  Every  word  that  is  the  name  of  some 
logical  concept  represents  intellectual  work — the  activ- 
ity of  judgment — in  its  formation.  In  learning  our 
language,  we  inherit  the  word  without  doing  the 
work."* 

A  word  or  two  should  be  added  regarding  the 
statement  that  judgment  is  the  assertion  of  a  single 
idea  and  that  the  subject  of  which  the  assertion  is 
made  is  the  system  of  facts  which  we  call  reality. 
"By  a  little  torture  of  expression  any  judgment  can 
be  thrown  into  a  form  in  which  undefined  reality  is 
the  general  subject,  and  the  whole  mass  of  the  judg- 
*  Creighton,  An  Introductory  Logic,  2nd.  ed.,  pp.  325-6. 


THE  NATURE  OF  REASONING  233 

ment  is  the  predicate.  '  William  Pitt  was  a  great 
statesman  '  =  '  There  was  a  great  statesman  named 
"William  Pitt  ' ;  '  The  three  angles  of  every  triangle 
are  equal  to  two  right  angles  '  =  '  There  are  figures 
known  as  triangles  with  their  three  angles  equal  to 
two  right  angles  ' ;  '  All  citizens  are  members  of  a 
moral  order  '  =  '  There  is  a  moral  order,  including 
the  relations  of  citizenship  ';  '  All  trespassers  will 
be  prosecuted  '  = '  Here  are  conditions  which  in- 
sure the  prosecution  of  possible  trespassers.'  Or  you 
might  always  put  a  subject,  '  Reality  is  such  that  ' — 
'  Reality  is  characterized  by. '  "  *  When  there  is  no 
explicit  differentiation  into  subject  and  predicate,  as 
in  the  case  of  '  it  is  raining, '  the  reality  to  which  the 
judgment  relates  is  relatively  undefined.  When  the 
differentiation  has  taken  place,  the  subject  term 
serves  to  point  out  the  place  at  which,  or  the  con- 
ditions under  which,  the  predicate  may  be  asserted 
of  reality. 

Negative  judgments,  such  as,  '  there  are  no  cen- 
taurs, '  have  the  same  subject  as  affirmative  judgments. 
A  judgment  like  the  above  may  readily  be  expressed 
as  meaning,  '  Reality  is  of  such  a  character  as  to 
exclude  centaurs. '  It  will  be  seen  that  negative  judg- 
ments are  not  merely  negative,  but  make  positive 
assertions.  In  order  to  make  an  intelligent  denial, 
it  is  necessary  to  be  in  possession  of  positive  informa- 
tion, and  hence  negative  judgments  carry  a  positive 
implication. 

Deduction,    Induction,    and  Circumstantial    Evi- 
dence.— It   is   customary  in   text-books  on   logic   to 
classify  arguments  as  deductive  and  inductive.     An 
*Bosanquet,  The  Esseniials  of  Logic,  pp.   107-8. 


234  AN  OUTLINE  OF  LOGIC 

inference  is  deductive  if  it  proceeds  from  a  universal 
to  a  particular,  in  the  manner  typified  in  the  first 
figure  of  the  syllogism.  On  the  other  hand,  an  infer- 
ence that  passes  from  particular  facts  to  a  generaliza- 
tion is  called  an  induction,  as  in  the  proof  of  uni- 
versal and  causal  connections. 

While  it  is  true  that  some  arguments  are  unmis- 
takably deductive  in  character  and  that  others  are 
just  as  unmistakably  inductive,  the  classification 
makes  no  provision  for  other  forms  of  argument,  and 
more  particularly  the  complex  forms  included  under 
circumstantial  evidence.  In  fact,  the  classification 
takes  account  only  of  the  more  obvious  and  simple 
kinds  of  inference.  In  circumstantial  evidence  we  may 
aim  to  prove  a  particular  fact  and  not  a  generalization, 
so  that  the  reasoning  cannot  be  called  inductive,  as 
the  word  has  just  been  defined.  But  on  the  other 
hand,  it  seems  equally  incorrect  to  call  it  a  deduction 
from  a  single  generalization.  We  do  not  first  have 
the  generalization  and  then  proceed  to  apply  it  to 
the  particular  fact,  but  the  complex  underlying  gen- 
eralization is  built  up  from  various  generalizations 
as  we  proceed.  We  do  not  proceed  from  the  universal 
to  the  particular,  but  universal  and  particular  are 
evolved  by  the  same  process.  In  all  reasoning  the 
aim  is  to  see  the  general  law  in  the  particular  case, 
but  this  end  may  be  attained  in  various  ways.  If, 
therefore,  the  terms  deduction  and  induction  are  used, 
it  should  be  remembered  that  they  do  not  cover  the 
whole  of  the  ground.  Sometimes  the  term  induction 
is  used  to  apply  to  all  the  forms  of  reasoning  em- 
ployed by  science.  As  thus  used,  however,  it  includes 
all  forms  of  inference.    The  scientist  employs  indue- 


THE  NATURE  OF  REASONING  235 

tion,  deduction — particularly  in  making  predictions, 
— and  circumstantial  evidence,  to  suit  the  occasion. 
If  induction  is  to  include  them  all,  the  term  has  no 
longer  any  distinctive  meaning  and  might  as  well 
be  discarded. 


CHAPTER  XV 
THE  AUTHORITY  OF  THE  TEST  OF  TRUTH 

The  Argument  for  Scepticism. —  In  the  foregoing 
discussions  it  has  been  contended  that  reasoning  must 
start  with  certain  fundamental  assumptions  or  postu- 
lates, such  as  the  uniformity  of  nature  and  the  relia- 
bility of  our  faculties.  These  cannot  be  proved  in 
advance,  but  must  be  justified  by  their  results.  This 
justification  is  furnished  by  the  convergence  of  evi- 
dence. When  the  various  items  of  our  experience 
combine  in  such  a  way  that  they  support  each  other 
and  suggest  no  ground  for  doubt,  we  have  all  the 
evidence  that  is  possible  or  necessary. 

It  may  be  argued,  however,  that  our  test  of  cer- 
tainty is,  after  all,  only  a  negative  test.  It  tells 
us  that  whenever  a  motivated  doubt  finds  standing 
ground,  there  certainty  has  not  yet  been  attained; 
but  it  does  not  guarantee  to  us  that  if  no  such  doubt 
can  be  found  we  may  be  sure  that  the  evidence  is 
sufficient.  The  doubt  may  not  be  found,  because  we 
did  not  examine  the  evidence  with  sufficient  care,  or 
because  some  of  the  facts  were  not  accessible.  The 
most  promising  chain  of  circumstantial  evidence  may 
suddenly  break  in  two.  In  spite  of  much  convergent 
evidence,  men  who  were  convicted  of  crimes  have 
turned  out  to  be  innocent;  the  sun  has  been  found 
not  to  move  about  the  earth,  and  '  light  as  air  '  has 

236 


THE  AUTHORITY  OF  THE  TEST  OF  TRUTH    237 

proved  to  be  a  myth.  Experience  has  shown  over 
and  over  again  that  the  human  mind  is  fallible,  even 
when  it  deems  itself  most  certain. 

Since  there  is  no  positive  test  by  which  we  may 
know  when  the  evidence  is  sufficient  for  certainty, 
it  may  plausibly  be  urged  that  there  is  no  belief 
which  is  beyond  the  reach  of  motivated  doubt.  The 
convergence  of  evidence  which  we  find  within  a  cer- 
tain circle  of  experience  may  be  upset  when  the  circle 
widens  so  as  to  admit  new  facts.  Our  total  ex- 
perience includes  at  best  but  a  small  fraction  of 
all  that  is  to  be  known.  In  view  of  this  situation, 
the  fact  that  we  have  erred  before  raises  a  presump- 
tion, however  small,  against  any  conclusion  that  we 
may  reach.  The  possibility  of  error,  even  when  no 
ground  can  be  found  for  a  motivated  doubt,  is  itself 
a  ground  for  motivated  doubt,  and  hence  the  entire 
structure  of  knowledge  is  reared  upon  a  foundation 
of  sand. 

It  seems  possible,  therefore,  to  play  the  sceptic  at 
every  point.  No  matter  what  the  special  issue  may 
be,  there  is  always  room  for  a  '  reasonable  '  doubt. 
Until  experience  is  all  in,  the  possibility  remains  that 
many  things  which  we  now  regard  as  indubitable  will 
be  overthrown.  To  what  extent  this  could  occur,  no 
man  can  say.  The  possible  experience  for  which  we 
must  make  allowance  is  of  indefinite  extent.  More- 
over, the  history  of  philosophy  seems  to  indicate  that 
in  his  endeavors  to  understand  the  constitution  of 
the  universe,  man  is  struggling  with  a  problem  which 
is  too  complex  for  his  powers;  or,  in  other  words, 
that  if  his  intellect  could  be  compared  with  that  of 
a  being  to  whom  all  the  secrets  of  the  universe  were 


238  AN  OUTLINE  OF  LOGIC 

revealed,  the  difference  would  be  overwhelming.  If 
this  be  the  case,  however,  it  may  well  be  that  to  such 
a  mind,  all  facts  would  appear  vastly  different  from 
the  way  in  which  they  appear  to  us,  and  that  our 
best-accredited  facts  are  little  more  than  caricatures 
of  the  truth. 

The  point  of  this  argument  is  that  the  experience 
of  error  in  the  past  justifies  a  doubt  in  each  new 
situation,  even  if  no  specific  fact  can  be  found  in 
the  new  situation  as  a  basis  for  the  doubt.  The 
question  thus  raised  is  whether  a  doubt  of  this  kind 
can  be  considered  a  motivated  doubt.  If  so,  the  door 
is  opened  to  a  most  radical  scepticism.  Not  only  is 
practical  certainty  an  impossibility,  since  no  amount 
of  evidence  can  eliminate  this  last  outstanding  doubt, 
but  the  doubt  may  be  considered  a  sufficient  warrant 
for  the  suspension  of  judgment  with  regard  to  any 
question  that  may  arise. 

Criticism  of  the  Argument. — This  reasoning,  how- 
ever, while  apparently  cogent,  involves  a  contradic- 
tion. It  claims  that  the  experience  of  error  makes 
certainty  impossible,  no  matter  how  much  evidence 
may  converge  upon  the  given  point.  The  convergence 
of  evidence,  then,  is  not  a  test  of  truth  which  can 
rid  us  of  a  paralyzing  doubt.  This  inference,  it  will 
be  seen,  takes  the  fact  of  error  for  granted  and  makes 
this  fact  its  point  of  departure.  But  how  do  we 
know  that  error  is  a  fact?  This  question  the  sceptic 
is  bound  to  answer  in  the  same  way  as  everybody 
else.  He  knows  this  on  the  basis  of  observation  and 
memory,  and  he  distinguishes  between  the  true  and 
the  false  in  his  observations  and  memories  by  means 
of  the  convergence  of  evidence.     In  other  words,  he 


THE  AUTHORITY  OF  THE  TEST  OF  TRUTH    239 

uses  precisely  the  same  test  of  truth  as  everybody 
else.  If,  however,  we  grant  his  contention  that  no 
such  convergence  of  evidence  can  compel  us  to  cast 
aside  our  doubt,  it  is  open  to  us  to  doubt  whether 
error  is  really  a  fact.  It  is  scarcely  legitimate  to 
assume  that  the  convergence  of  evidence  is  competent 
to  establish  beyond  doubt  the  fact  of  error,  and  then 
to  use  this  fact  in  order  to  prove  that  the  convergence 
of  evidence  cannot  establish  a  fact  of  any  kind.  If, 
therefore,  the  experience  of  error  is  made  a  basis  for 
universal  doubt,  the  doubt  itself  reinstates  the  test 
of  truth  which  it  is  supposed  to  overthrow. 

The  inference,  then,  which  we  seem  compelled  to 
draw,  is  that  the  experience  of  error  is  not  a  sufficient 
warrant  for  doubt,  unless  the  previous  experience  is 
a  parallel,  in  some  specific  feature,  to  the  case  which 
is  affected  by  the  doubt.  That  errors  have  occurred 
is  a  fact  which  has  absolutely  no  bearing  upon  the 
question  of  the  truth  or  falsity  of  a  given  inference, 
except  in  so  far  as  the  present  case  is  like  those  other 
cases.  Errors  have  occurred  in  the  past  and  will 
occur  in  the  future,  but  every  one  is  justified,  accord- 
ing to  logical  standards,  if,  after  a  proper  scrutiny 
of  the  facts  has  failed  to  reveal  any  specific  reason 
for  a  doubt,  he  treats  the  conclusion  as  a  certainty. 
We  cannot  assume,  as  this  form  of  scepticism  does, 
that  some  knowledge  is  reliable,  and  then  infer,  by 
means  of  this  assumption,  that  the  whole  of  knowl- 
edge is  unreliable.  If  a  doubt  is  cast  upon  all  knowl- 
edge, the  doubt  is  necessarily  of  the  unmotivated  kind. 
In  general  we  may  say  that  a  scepticism  which  at- 
tempts to  motivate  its  doubts,  i.e.,  a  scepticism  which 
gives  its  reasons,  is  always  inconsistent  with  itself, 


240  AN  OUTLINE  OF  LOGIC 

because  it  assumes  in  its  premises  a  test  of  truth 
which  it  denies  in  its  conclusion. 

Unreasoned  Scepticism. — If  we  grant  that  the- 
oretical scepticism,  i.e.,  the  scepticism  which  defends 
itself  with  reasons,  can  be  convicted  of  inconsistency, 
there  remains  only  one  other  form  of  scepticism,  viz., 
the  scepticism  which  does  not  seek  to  justify  itself 
by  argument.  It  may  be  that  human  beings,  con- 
stituted as  they  are,  must  necessarily  rely  upon  the 
convergence  of  evidence  as  a  test  of  truth,  if  they 
are  to  reason  at  all,  but  this  does  not  prove  that 
the  test  of  truth  which  they  employ  is,  in  fact,  a 
reliable  test.  As  was  suggested  a  moment  ago,  our 
best-accredited  results  may  be  nothing  but  a  tissue 
of  error,  a  source  of  laughter  for  the  gods.  Our  test 
of  truth  does  indeed  forbid  unmotivated  doubt,  but 
the  authority  of  this  test  cannot  be  established  by 
arguments  which  do  not  presuppose  it,  nor  is  this 
authority  a  self-evident  fact.  If,  therefore,  the  au- 
thority of  the  test  of  truth  be  denied,  until  its  claim 
has  been  established  by  reasoning,  we  have  a  form 
of  scepticism  that  is  invulnerable  to  argument.  On 
what  grounds,  then,  does  this  authority  rest?  What 
right  have  we  to  assert  that  every  doubt  must  be 
motivated  ? 

The  Non-Rational  Basis  for  the  Test  of  Truth.— 
The  answer  to  the  questions  just  raised  is  that  un- 
motivated doubt  is  incompatible  with  the  conditions 
of  our  existence.  If  we  were  mere  bystanders  in  the 
game  of  life,  with  absolutely  no  needs  of  any  sort, 
and  with  .no  desire  for  knowledge,  an  attitude  of 
unmotivated  doubt  would  not  be  so  utterly  impossible 
as  we  now  find  it  to  be.     The  game  is  so  intensely 


THE  AUTHORITY  OF  THE  TEST  OF  TRUTH    241 

real  to  us  because  we  are  participants  in  it.  To  the 
average  healthy-minded  person  an  attitude  of  doubt 
on  all  questions  would  rightly  be  regarded  as  a  hope- 
less abnormality,  since  it  would  leave  no  room  for 
any  of  our  spontaneous  beliefs  or  for  any  intelligent 
activity.  To  the  common-sense  man  such  an  attitude 
'  makes  no  sense.'  We  insist  that  doubt  shall  be 
motivated,  because  we  are  constrained  thereto,  not 
by  argument,  but  by  the  various  impulses  of  our 
being,  both  cognitive  and  practical,  which  clamor  for 
expression. 

According  to  this  view,  the  overpowering  sense  of 
reality  which  we  ordinarily  have  in  the  presence  of 
our  environment,  and  which  is  so  foreign  to  the 
attitude  of  doubt,  betokens  the  action  of  good  healthy 
red  blood  in  our  veins.  It  is  not  surprising,  there- 
fore, that  in  certain  abnormal  cases  this  sense  of 
reality  should  be  considerably  diminished.  "  In  cer- 
tain forms  of  melancholic  perversion  of  the  sensi- 
bilities and  reactive  powers,  nothing  touches  us  in- 
timately, rouses  us,  or  weakens  natural  feeling.  The 
consequence  is  the  complaint  so  often  heard  from 
melancholic  patients,  that  nothing  is  believed  by  them 
as  it  used  to  be,  and  that  all  sense  of  reality  is  fled 
from  life.  They  are  sheathed  in  India-rubber;  noth- 
ing penetrates  to  the  quick  or  draws  blood,  as  it 
were.  .  .  .  '  I  see,  I  hear,'  such  patients  say,  '  but 
the  objects  do  not  reach  me,  it  is  as  if  there  were 
a  wall  between  me  and  the  outer  world. '  "  *  The 
same  writer  quotes,  as  an  illustration,  the  following: 
"  '  When  I  reflect  on  the  fact  that  I  have  made  my 
appearance  by  accident  upon  a  globe  itself  whirled 
*  James,  Psychology,  Vol.  II.,  p.  298. 


242  AN  OUTLINE  OF  LOGIC 

through  space  as  the  sport  of  the  catastrophes  of 
the  heavens,'  says  Madame  Ackerman;  '  when  I  see 
myself  surrounded  by  beings  as  ephemeral  and  in- 
comprehensible as  I  am  myself,  and  all  excitedly  pur- 
suing pure  chimeras,  I  experience  a  strange  feeling 
of  being  in  a  dream.  It  seems  to  me  as  if  I  have 
loved  and  suffered  and  that  ere  long  I  shall  die,  in 
a  dream.  My  last  word  will  be,  I  have  been  dream- 
ing. '  "  * 

The  reason,  then,  why  we  accept  the  test  of  truth 
and  disregard  unmotivated  doubt  is  that  the  only 
alternative  to  this  is  the  stagnation  of  all  our  mental 
and  physical  powers.  An  uncompromising  scepticism 
of  this  kind  is  so  intolerably  artificial  to  us  because 
it  is  so  completely  out  of  accord  with  the  natural 
tendencies  of  our  being.  It  proposes  to  condemn  us 
to  a  state  of  inglorious  passivity,  a  proposal  against 
which  all  our  normal  impulses  arise  in  protest.  Since 
this  protest  is  too  strong  to  be  disregarded,  we  accept 
as  our  test  of  truth  the  convergence  of  evidence,  and 
we  legitimate  the  results  achieved  through  its  aid  by 
ruling  this  all-destroying  doubt  out  of  court. 

To  What  Extent  Our  Interests  May  Properly 
Determine  Belief. — According  to  the  position  main- 
tained in  the  preceding  paragraph,  all  inference  rests 
ultimately  upon  assumptions  which  are  non-rational 
in  character,  i.e.,  assumptions  which  have  no  evidence 
in  their  favor.  These  assumptions  are  made  because 
it  suits  our  purpose  or  interests  to  do  so.  Or,  to  be 
a  little  more  accurate,  we  make  certain  unproved 
and   unprovable    assumptions   right   from   the   start, 

*  The  Varieties  of  Religious  Experience,  p.  63.  Cf.  also  The 
Will  to  Believe,  Chapter  I.,  by  the  same  author. 


THE  AUTHORITY  OF  THE  TEST  OF  TRUTH    243 

without  knowing  that  we  do  so,  but  simply  because 
we  are  built  that  way.  Later  on,  when  we  turn 
logicians  and  reflect  upon  our  methods,  we  discover 
what  we  have  been  doing,  and  we  then  find  that  no 
reasons  can  be  adduced  in  justification  of  this  pro- 
cedure, except  reasons  of  a  practical  kind.  Our  next 
question  is  to  what  extent  this  appeal  to  practical 
reasons  is  legitimate.  Is  it  permissible  to  believe 
whatever  we  may  find  necessary  to  '  avert  the  stagna- 
tion of  all  our  mental  and  physical  powers  '? 

This  question  is  of  interest,  because  the  appeal  to 
practical  need  may  on  occasion  seem  to  claim  more 
authority  than  we  are  entitled  to  accord  to  it.  An 
instance  of  such  appeal  is  found  in  the  following  lines 
from  Tennyson : 

My  own  dim  life  should  teach  me  this, 
That  life  shall  live  for  evermore, 
Else  earth  is  darkness  at  the  core, 
And  dust  and  ashes  all  that  is; 

This  round  of  green,  this  orb  of  flame, 
Fantastic  beauty;  such  as  lurks 
In  some  wild  poet,  when  he  works 
Without  a  conscience  or  an  aim. 

What  then  were  God  to  such  as  I? 
'Twere  hardly  worth  my  while  to  choose 
Of  things  all  mortal,  or  to  use 
A  little  patience  ere  I  die; 

'Twere  best  at  once  to  sink  to  peace, 
Like  birds  the  charming  serpent  draws, 
To  drop  head-foremost  in  the  jaws 
Of  vacant  darkness  and  to  cease.* 

*  In  Memoriam,  XXXIV. 


244  AN  OUTLINE  OF  LOGIC 

At  first  sight  the  position  here  taken  by  Tennyson 
is  identical  with  the  one  defended  in  this  chapter. 
Tennyson  argues  that  without  the  belief  in  immor- 
tality, '  earth  is  darkness  at  the  core,'  and  he  seems 
to  imply  that  this  fact  legitimates  the  belief.  In  a 
similar  way  we  have  reasoned  that  our  test  of  truth 
is  validated  by  the  fact  that  its  rejection  involves 
consequences  which  we  are  unwilling  to  accept. 

A  closer  comparison,  however,  reveals  an  important 
difference  between  the  two  cases.  In  accepting  the 
test  of  truth  we  commit  ourselves,  indeed,  to  a  certain 
mode  of  procedure,  but  we  do  not  determine  in  ad- 
vance what  specific  facts  our  world  is  to  contain. 
In  adopting  this  test  we  are  obliged  to  pin  our  faith 
to  the  uniformity  of  nature  and  to  the  reliability  of 
our  faculties,  but  what  particular  uniformities  or 
what  particular  facts  we  shall  find,  experience  alone 
can  reveal.  In  other  words,  we  can  try  our  hand  at 
reasoning  or  abstain,  as  we  may  prefer;  but  if  we 
care  to  make  an  attempt,  we  must  abide  by  the  rules 
of  the  game.  In  justifying  the  validity  of  our  test 
of  truth  by  an  appeal  to  our  practical  needs,  we 
justify  a  method  or  mode  of  procedure,  and  this 
method  determines  how  the  belief  in  specific  facts 
is  to  be  supported.  Hence  the  principles  of  reason- 
ing can  at  first  be  accepted  unconsciously;  there  is 
no  conscious  belief  in  the  validity  of  these  principles 
until  reflection  has  shown  us  what  is  implied  in 
inference.  But  to  justify  the  belief  in  a  particular 
fact,  such  as  immortality,  by  our  practical  needs,  is 
a  different  matter.  Here  we  necessarily  start  with 
a  conscious  belief,  and  this  belief,  however  important 
it  may  be,  is  not  indispensable  to  inference.    The  fact 


THE  AUTHORITY  OF  THE  TEST  OF  TRUTH  245 

in  question  is  the  same  kind  of  fact,  so  far  as  logic 
is  concerned,  as  the  facts  which  are  established  by- 
convergence  of  evidence.  The  appeal,  therefore,  to 
practical  needs,  instead  of  convergence  of  evidence, 
means  that  we  employ  two  standards  or  tests  of  truth 
instead  of  one.  In  this  second  criterion  we  not  only 
assume  that  the  universe  is  of  such  a  character  as 
to  satisfy  our  fundamental  needs,  but  we  become  in- 
volved in  the  difficulty  that  the  two  standards  may 
conflict.  Since  the  two  standards  are  on  equal  foot- 
ing, one  has  as  much  claim  to  prevail  as  the  other; 
and  so  it  may  happen  that  the  individual  feels  justi- 
fied in  setting  aside  the  available  evidence,  if  it  con- 
flicts with  his  cherished  desires.  That  such  a  course 
would  be  justified  seems  to  be  asserted  by  Tennyson, 
when,  in  arguing  against  materialism,  he  maintains 
that  men  are, 

Not  only  cunning  casts  in  clay: 
Let  Science  prove  we  are,  and  then 
What  matters  Science  unto  men, 
At  least  to  me1?    I  would  not  stay.* 

Such  an  attitude,  it  is  plain,  robs  our  test  of  truth 
of  all  authority.  If  evidence,  in  the  ordinary  sense 
of  the  term,  may  be  set  aside  at  one  point,  because 
it  happens  to  be  distasteful,  it  may  be  set  aside  at 
all  points.  We  cannot  afford  to  play  fast  and  loose 
with  our  criterion.  To  withhold  our  consent  when 
the  evidence  is  conclusive  is  to  forswear  rationality. 
Reason  is,  indeed,  merely  another  name  for  that  har- 
mony of  our  experiences  which  we  have  called  con- 
*Ibid.,  CXX. 


246  AN  OUTLINE  OF  LOGIC 

vergence  of  evidence.  We  conclude,  therefore,  that 
desire  justifies  the  acceptance  of  the  principles  of 
reasoning,  or  '  the  rules  of  the  game, '  but  that  it  does 
not  warrant  the  belief  in  anything  else. 

Belief  and  Evidence. — The  conclusion  just  reached 
inevitably  raises  a  further  question.     Granted  that 
we  are  not  permitted  to  reject  any   fact  which   is 
established   by   convergence   of   evidence,    is   it    also 
true  that  we  are  entitled  to  believe  nothing  except 
what    is    accredited   by    the    same    test?      If   man's 
sole  business  in  life  were  the  pursuit  of  science,  this 
conclusion  would  perhaps  be  tenable.     Yet  even  in 
science  we  may  rely  upon  unanalyzed  '  impressions,' 
in  the  hope  that  some  day  our  faith  will  be  justified. 
Thus  Linnaeus  is  reported  to  have  said,  regarding  his 
classification  of  species,  "  I  will  not  give  my  reasons 
for  the  distribution  of  the  natural  orders  which  I 
have  published.     You  or  some  other  persons,   after 
twenty  or  after  fifty  years,  will  discover  them  and 
see  that  I  was  right."*     The   discovery  thus  pre- 
dicted was  realized  when  it  was  found  that  Linnaeus 
had  unconsciously  been  classifying  along  the  lines  of 
evolution   or  descent.     In   the   preceding   pages   our 
attention  has  at  various  times  been  called  to  the  fact 
that  inarticulate  perception  or  '  intuition  '  constantly 
outruns  our  powers  of  analysis  and  formulation.    The 
degree  of  assurance  inspired  by  such  intuitions  may 
be  immeasurably  greater  than  our  ability  to  justify 
them.     Yet  such  assurance  cannot  be  condemned,  if 
we  hold  it  at  all  times  subject  to  the  results  of  inquiry 
and  evidence. 

To  apply  this  in  detail  to  matters  of  religious  belief 

•Romanes,  Darwin  and  After  Darwin,   Vol.   I.,  p.  ^6. 


THE  AUTHORITY  OF  THE  TEST  OF  TRUTH    247 

would  carry  us  too  far  afield.  In  general,  however, 
we  may  say  that  if  the  drift  of  a  person's  experience 
leads  him  to  some  belief,  such  as  that  in  "  a  power 
not  ourselves  that  makes  for  righteousness,"  or  in 
a  future  life,  but  if  he  is  at  all  times  open  to  evidence, 
such  belief  is  not  in  conflict  with  logic.  Just  as  we 
may  react  in  a  very  definite  way  to  the  impression 
made  upon  us  by  a  particular  person  or  a  given 
situation,  so  we  may  react  in  a  definite  and  vivid  way 
upon  life  as  a  whole.  "We  may  be  strongly  persuaded 
that  the  powers  that  be  and  upon  which  our  destiny 
depends  are  divine  or  that  they  are  diabolic,  without 
being  able  to  give  the  reasons  for  our  belief.  Apart 
from  specific  evidence,  a  religious  belief  of  this  kind 
is  properly  a  tentative  faith  or  hope  in  things  seen 
through  a  glass,  darkly;  a  working  hypothesis,  and 
not  a  dogmatic  and  irrevocable  conclusion.  Held  in 
this  way,  the  belief  violates  none  of  the  canons  of 
logic,  although  it  is  held  without  evidence,  in  the 
sense  that  the  evidence  in  question  is  insusceptible 
of  formulation.  Since  the  evidence  cannot  be  set 
down  in  detail,  it  scarcely  admits  of  close  scrutiny 
and  critical  evaluation.  For  this  reason  the  belief 
commends  itself  primarily  only  to  the  person  directly 
concerned;  a  fact  which  indicates  why  religious  be- 
liefs, in  common  with  certain  other  beliefs,  are  to 
a  large  extent  essentially  of  a  private  and  incom- 
municable character.* 

Mysticism  and  the  Test  of  Truth. — It  has  some- 
times been  claimed,  in  the  interests  of  religion,  that 
certain  things  can  be  known  without  reliance  upon 

♦Compare  W.  K.  Clifford,  "The  Ethics  of  Belief,"  in 
Lectures  and  Essays,  Vol.  II. 


248  AN  OUTLINE  OF  LOGIC 

this  test  of  truth.  Religious  truth,  it  is  said,  comes 
to  us  through  a  unique  channel  and  it  comes  properly 
accredited,  but  its  credentials  are  not  furnished  by 
convergence  of  evidence.  Certain  facts,  such  as  the 
existence  of  God  and  his  attitude  towards  the  in- 
dividual, the  divine  character  of  Scripture,  or  the 
efficacy  of  a  certain  plan  of  salvation,  are  known  to 
us  in  a  way  that  is  totally  different  from  our  ordinary 
forms  of  knowing,  and  in  a  way  that  neither  admits 
of  description  nor  requires  any  support  from  other 
experiences.  The  experiences  in  which  this  knowl- 
edge comes  share  with  sense-perception  the  quality 
of  immediacy,  i.e.,  they  are  not  inferential  or  mediate 
in  character.  They  are,  however,  totally  different 
from  perception  in  other  respects.  They  involve  no 
special  sense-organ,  and  they  are  not  confined  to 
physical  objects.  These  experiences  are  incommunica- 
ble or  ineffable;  and  they  usually  go  by  the  name  of 
mystical  experiences.  As  a  rule,  they  are  conclusive 
evidence,  for  the  person  who  possesses  them,  of  the 
truths  which  they  attest ;  but  since  they  are  personal 
and  unsharable  experiences,  they  cannot  compel  the 
belief  of  others. 

As  against  the  general  claim  that  there  are  other 
forms  of  knowing  besides  those  which  we  have  been 
studying,  it  would  doubtless  be  unwarranted  to  enter 
a  general  denial,  without  taking  evidence  on  the 
subject.  How  many  different  forms  of  knowing  there 
may  be  we  have  no  right  to  determine  dogmatically  in 
advance.  It  must  be  insisted,  however,  that  if  this 
new  knowledge  conflicts  with  the  knowledge  which 
has  been  discussed  in  the  preceding  pages,  the  claims 
of  this  latter  knowledge  must  be  allowed,  unless  we 


THE  AUTHORITY  OF  THE  TEST  OF  TRUTH  249 

are  willing  to  discredit  the  entire  body  of  ordinary 
human  experience.  Our  logic  has  no  right  to  decide 
that  other  forms  of  knowing  are  impossible,  but 
neither  can  it  recognize  any  claims  that  conflict  with 
its  own.  Thus  the  facts  of  science  may  point  to 
evolution  as  the  process  by  which  things  came  to  be 
as  they  are,  whereas  a  revelation  which  is  attested 
by  mystical  experiences  may  assert  that  the  explana- 
tion lies  in  the  special  creation  of  fixed  and  immutable 
types.  Wherever  such  disagreement  occurs,  the  proof 
that  rests  upon  convergence  of  evidence  must  be  ac- 
cepted, since  we  otherwise  destroy  the  authority  of 
the  test  of  truth  and  open  the  door  to  a  scepticism, 
with  regard  to  our  everyday  experiences,  that  is  as 
radical  as  can  be  imagined.  In  other  words,  if  we 
assume,  for  the  sake  of  the  argument,  that  there  are 
forms  of  knowing  which  do  not  depend  upon  the 
facts  of  sense-observation  and  memory,  and  infer- 
ences from  these  facts,  we  must  nevertheless  insist 
that  such  knowledge  is  subject  to  the  same  test  as 
all  other  knowledge.  All  experiences  have  a  prima 
facie  claim  to  be  true.  The  credibility  of  this  other 
knowledge  may  be  strengthened  by  the  convergence 
of  evidence,  and  weakened  by  its  incompatibility  with 
knowledge  acquired  in  the  usual  way.  The  test  of 
truth  is  applicable  to  all  knowledge,  regardless  of  its 
origin. 

The  fact,  then,  that  experiences  such  as  those  called 
mystical  are  different  in  kind  from  ordinary  ex- 
periences does  not  exempt  their  deliverances  from  the 
authority  of  the  test  of  truth.  And  unless  we  aban- 
don all  rational  standards  of  thinking,  we  are  bound 
to   conclude   that   mystical   experiences   may   testify 


250  AN  OUTLINE  OF  LOGIC 

to  error.  These  experiences  contradict  each  other 
in  such  a  way  that  no  other  conclusion  is  possible. 
Religious  mysticism  "  has  been  both  ascetic  and  anti- 
nomianly  self-indulgent  within  the  Christian  church. 
It  is  dualistic  in  Sankhya,  and  monistic  in  Vedanta 
philosophy.  I  called  it  pantheistic;  but  the  great 
Spanish  mystics  are  anything  but  pantheists.  They 
are  with  few  exceptions  non-metaphysical  minds,  for 
whom  '  the  category  of  personality  '  is  absolute.  The 
'  union  '  of  man  with  God  is  for  them  much  more 
like  an  occasional  miracle  than  like  an  original  iden- 
tity. How  different  again,  apart  from  the  happiness 
common  to  all,  is  the  mysticism  of  Walt  Whitman, 
Edward  Carpenter,  Richard  Jeffries,  and  other  nat- 
uralistic pantheists,  from  the  more  distinctively  Chris- 
tion  sort.  The  fact  is  that  the  mystical  feeling  of 
enlargement,  union,  and  emancipation  has  no  specific 
intellectual  content  whatever  of  its  own.  It  is  capable 
of  forming  matrimonial  alliances  with  material  fur- 
nished by  the  most  diverse  philosophies  and  theologies, 
provided  only  they  can  find  a  place  in  their  frame- 
work for  its  peculiar  emotional  mood.  We  have  no 
right,  therefore,  to  invoke  its  prestige  as  distinctively 
in  favor  of  any  special  belief,  such  as  that  in  absolute 
idealism,  or  in  the  absolute  monistic  identity,  or  in 
the  absolute  goodness,  of  the  world.  It  is  only  rela- 
tively in  favor  of  all  these  things — it  passes  out  of 
common  human  consciousness  in  the  direction  in 
which  they  lie."  * 

Whether  mystical  experiences  are  entitled  to  serious 
consideration  as  revelations  of  truth  or  are  to  be 
sot  aside  as  a  mere  psychological  peculiarity  of  cer- 

*  James,   The   Varieties   of  Religious   Experience,   p.   425. 


THE  AUTHORITY  OF  THE  TEST  OF  TRUTH    251 

tain  persons,  is  a  question  about  which  experts  are 
not  agreed.  Since  the  question  falls  outside  the  do- 
main of  logic,  we  can  afford  to  leave  it  undecided 
here.  But  if  we  assume  that  they  are  a  genuine 
source  of  information,  we  can  at  best  treat  them 
only  as  we  should  treat  our  new  experiences,  if  we 
were  suddenly  endowed  with  a  sixth  sense.  Let  us 
suppose  that  on  the  strength  of  his  mystical  ex- 
periences a  person  believes  that  there  is  a  soul  of 
goodness  in  things  evil,  a  divinity  that  somehow 
shapes  our  ends.  How  he  knows  this  he  is,  of  course, 
quite  unable  to  state,  yet  this  conviction  may  be  as 
deep-rooted  as  the  belief  in  the  reality  of  an  ex- 
ternal world  or  in  our  own  personal  existence.  We 
have  here  a  form  of  testimony  which,  as  to  its  direct- 
ness, is  very  much  like  recollection  and  sense-percep- 
tion.* All  these  forms  of  direct  testimony  may  at 
a  later  time  turn  out  to  be  wrong,  but  they  seem 
to  be  true  when  they  present  themselves,  and  they 
all  make  exactly  the  same  demand  upon  our  faith. 
We  have  seen  before  that  we  cannot  first  stop  and 
argue  whether  our  observations  and  recollections  are 
reliable.  Such  a  procedure  would  stultify  the  quest 
for  knowledge  from  the  start.  If  this  condition  is 
unreasonable  in  the  case  of  observation  and  memory, 
the  same  is  true  with  regard  to  mystical  experiences, 
provided  it  cannot  be  shown  satisfactorily  that  these 
experiences  are  erroneous  from  start  to  finish.  They 
would  then  have  the  same  right  to  be  heard,  and 
they  could  be  condemned  only  by  the  combined  testi- 
mony of  other  experiences.    In  so  far  as  the  mystical 

*  Cf.  Matthew  Arnold,  "  Our  Masses  and  the  Bible,"  Section 
III.,  in  Literature  and  Dogma. 


252  AN  OUTLINE  OF  LOGIC 

experience  asserted  facts  that  conflict  with  facts  estab- 
lished by  convergence  of  evidence,  it  would  be  dis- 
credited. In  so  far  as  it  could  claim  the  support 
of  other  facts  it  would  be  proved.  In  so  far  as  it 
were  neither  proved  nor  disproved  by  other  facts,  its 
position  would  correspond  to  that  of  an  unsupported 
postulate.  Logically  the  belief  could  not  be  con- 
demned, although  it  might  prove  to  be  wrong.  The 
test  of  truth  is  rightfully  the  same  for  the  mystic 
and  the  non-mystic,  but  unless  the  mystical  experience 
can  be  discredited,  we  are  bound  to  conclude  that 
human  experience  has  not  proceeded  far  enough  or 
is  not  wide  enough  to  show  definitely  which  stand- 
point is  correct.  Hence  the  mystic  makes  constant 
appeal  to  his  peculiar  experience  as  presumptive  evi- 
dence for  his  position;  but  since  this  experience  is 
not  shared  by  his  opponent,  the  latter  refuses  to  con- 
cede that  this  evidence  is  entitled  to  recognition. 
While  the  test  of  truth  is  the  same,  the  data  are 
different  in  the  two  cases,  and  this  necessitates  a 
difference  in  the  ultimate  conclusions. 

These  considerations  enable  us  to  see  why  it  is  that, 
although  religions  constantly  change,  religion  never- 
theless endures.  Whether  the  religion  be  based  upon 
inarticulate  '  impression  '  or  upon  mysticism,  or  upon 
both,  the  individual  naturally  and  inevitably  inter- 
prets his  religious  experiences  in  the  light  of  the 
knowledge  that  he  happens  to  possess;  and  as  this 
knowledge  grows,  a  change  in  his  religious  beliefs 
becomes  inevitable.  The  '  power  not  ourselves  that 
makes  for  righteousness  '  may  be,  and  has  been,  in- 
terpreted in  many  different  ways,  conception  after 
conception  having  been  discarded  as  inadequate  in 


THE  AUTHORITY  OF  THE  TEST  OP  TRUTH  253 

the  progress  from  savagery  to  civilization.  The  un- 
tenability  of  former  beliefs  does  not  necessarily  or 
as  a  rule  result  in  the  conviction  that  religious  ex- 
periences are  essentially  untrustworthy,  but  it  merely 
suggests  that  these  experiences  have  been  wrongly 
interpreted.  As  long,  therefore,  as  these  experiences 
continue,  the  individuals  that  possess  them  will  tend 
to  persist  in  the  belief  that  there  is  an  unseen  order 
of  things  upon  which  the  visible  and  tangible  things 
of  everyday  life  are  somehow  dependent ;  and  he  will 
try,  as  best  he  may,  to  bring  this  belief  into  harmony 
with  the  totality  of  his  other  beliefs. 

We  may  sum  up  the  preceding  discussion  in  this 
way:  Unless  we  are  prepared  to  maintain  an  attitude 
of  scepticism  towards  the  entire  body  of  organized 
human  experience,  we  are  compelled  to  recognize  as 
supreme  the  authority  of  our  test  of  truth.  If  the 
facts  cohere  in  such  a  manner  as  to  support  each 
other,  they  are  and  must  be,  so  far  forth,  accepted 
as  true.  Conversely,  any  experience  that  makes 
against  the  whole  weight  of  evidence  which  is  fur- 
nished by  our  other  experiences  must  be  accounted 
a  delusion.  There  is,  however,  in  the  mind  of  each 
person  a  region  that  has  not  yet  been  annexed  by 
scientific  exploration.  Belief  on  the  ground  of  un- 
analyzed  evidence  or  '  intuition  '  is  logically  per- 
missible, on  condition  that  all  tangible  evidence  be 
accorded  due  recognition  when  it  presents  itself. 
Furthermore,  every  form  of  experience  raises  an  ante- 
cedent presumption  of  its  truth.  If  such  presumptive 
truth  is  asserted  for  observation  and  memory,  it  can- 
not be  denied  to  mystical  experiences,  unless  we  have 
reason    to    think    that    important    differences    exist. 


254  AN  OUTLINE  OF  LOGIC 

Finally,  all  doubts  that  have  no  other  basis  than 
the  fact  that  errors  may  occur  even  when  the  evidence 
seems  decisive,  are  treated  as  unmotivated  doubts. 
This  is  done  because  doubt  on  such  terms  would  in- 
hibit all  activity  and  thus  do  violence  to  all  our 
spontaneous  demands  and  tendencies.  It  appears, 
therefore,  that  the  authority  of  the  test  of  truth  can- 
not be  successfully  defended  against  all  doubt  by 
argument,  but  that  the  ultimate  sanction  or  warrant 
for  this  authority  springs  from  the  demand  which 
we  make  upon  our  environment. 


CHAPTER  XVI 

THE  PROBLEM  OF  SENSE-PERCEPTION 

It  has  previously  been  argued  that  the  trustworthi- 
ness of  observation  is  a  postulate  of  reasoning.  We 
get  a  start  by  taking  for  granted  that  sense-percep- 
tion can  give  us  a  certain  measure  of  truth  concern- 
ing the  nature  of  our  surroundings.  This  faith  finds 
constant  justification  in  everyday  life.  By  trusting 
our  perceptions  we  find  it  possible  to  adjust  our- 
selves to  our  environment  in  such  a  way  as  to  profit 
by  what  is  expedient  for  us  and  to  avoid  what  is 
injurious.  Sense-perception  enables  us  to  provide  for 
our  daily  wants  and  to  protect  ourselves  against  the 
dangers  which  constantly  threaten  our  existence  or 
our  well-being. 

The  Subjectivity  of  Sense-Qualities.— Although  it 
cannot  be  denied  that  sense-perception  is  adapted 
to  the  purpose  of  securing  adjustment,  the  question 
still  remains  whether  it  presents  objects  to  us  '  just 
as  they  are,'  i.e.,  whether  the  object  is  perceived  just 
as  it  exists  when  it  is  not  perceived.  This  problem, 
which  common  sense  scarcely  considers,  has  been  the 
subject  of  much  debate  and  wide  divergence  of 
opinion. 

In  order  to  appreciate  the  nature  of  the  problem 
we  must  consider  how  it  arises.  As  long  as  we  do 
not  reflect  upon  the  matter,  we  are  inclined  to  ascribe 

255 


256  AN  OUTLINE  OF  LOGIC 

all  perceived  qualities  directly  to  the  object.  Certain 
experiences,  however,  force  us,  apparently,  to  dis- 
tinguish between  what  belongs  to  the  object  and  what 
is  '  in  the  mind.'  Thus  the  pain  resulting  from  the 
prick  of  a  pin  or  from  a  burn  is  not  supposed  to 
reside  in  the  pin  or  in  the  fire,  but  in  the  mind. 
Similarly  a  lump  of  sugar  is  assumed  to  be  sweet  and 
a  rose  to  be  fragrant  only  in  the  sense  that  when 
we  respectively  taste  or  smell  these  objects  we  have 
the  experience  of  sweetness  or  fragrance.  The  sugar 
by  itself  is  not  sweet,  but  it  has  the  power  of  giving 
us  a  certain  taste-sensation,  and  a  similar  judgment 
is  held  with  respect  to  the  fragrance  of  the  rose. 
"  Sweetness  is  not  really  in  the  sapid  thing,  because, 
the  thing  remaining  unaltered,  the  sweetness  is 
changed  into  bitter,  as  in  the  case  of  fever  or  other- 
wise vitiated  palate."* 

This  distinction  between  qualities  which  inhere  in 
objects  and  qualities  which  exist  only  in  conscious- 
ness tends  to  appear  also  in  connection  with  other 
sense-qualities.  "  He  that  will  consider  that  the  same 
fire  that  at  one  distance  produces  in  us  the  sensation 
of  warmth,  does  at  a  nearer  approach  produce  in 
us  the  far  different  sensation  of  pain,  ought  to  be- 
think himself  what  reason  he  has  to  say  that  this 
idea  of  warmth,  which  was  produced  in  him  by  the 
fire,  is  actually  in  the  fire;  and  his  idea  of  pain, 
which  the  same  fire  produced  in  him  the  same  way, 
is  not  in  the  fire."t  It  was  observed  long  ago  that 
if  one  of  our  hands  is  cold,  and  the  other  warm,  and 

*  Berkeley,  Principles  of  Human  Knowledge,  Part  I.,   §  14. 
I  Locke,  Essay  on  the  Human  Understanding,  Book  II.,  Chap- 
ter \  III,   §  K5. 


THE  PROBLEM  OF  SENSE-PERCEPTION       257 

if  we  put  both  into  a  vessel  of  tepid  water,  the  water 
will  seem  warm  to  the  one  hand  and  cold  to  the 
other.  Since  the  water  cannot  be  both  warm  and 
cold  at  the  same  time,  the  suggestion  arises  that  these 
perceptions  are  purely  mental  facts.  This  suggestion 
is  supported  by  physical  science,  which  reduces  heat 
to  a  certain  motion  of  air-waves.  These  air-waves, 
it  seems,  are  in  themselves  neither  warm  nor  cold, 
but  they  are  capable  of  causing  sensations  of  warm 
and  cold  whenever  they  act  upon  our  sense-organs. 
Warm  and  cold,  therefore,  are  qualities  that  do  not 
belong  to  objects,  but  are  dependent  for  their  exist- 
ence upon  consciousness. 

The  reason  why  we  are  disposed  to  accept  this 
conclusion  appears  to  be  twofold.  In  the  first  place, 
we  find  it  difficult  to  conceive  what  a  taste  or  a 
temperature  may  be  apart  from  a  consciousness  for 
which  it  exists.  We  realize  that  these  qualities  are 
necessarily  relative  to  some  sense-organ.  How  sweet 
or  how  warm  an  object  is  depends  upon  the  condition 
of  our  sense-organs,  and  we  can  discover  no  reason 
why  one  condition  of  the  sense-organ  rather  than 
another  should  be  set  up  as  the  standard  condition. 
In  other  words,  we  are  unable  to  discover  any  abso- 
lute standard  for  the  measurement  of  these  qualities 
as  they  might  be  supposed  to  exist  when  not  ex- 
perienced. Every  actual  experience  of  taste  and 
temperature  is  determined  by  the  relation  of  the 
stimulus  to  a  certain  sense-organ,  and  from  this  circle 
of  relativity  we  can  find  no  means  of  escape.  In  the 
second  place,  physical  science  seems  able  to  explain 
these  experiences  in  terms  of  cause  and  effect.  The 
thermometer  does  not  measure  temperature  directly, 


258  AN  OUTLINE  OF  LOGIC 

but  records  the  expansion  of  the  mercury.  When  the 
conditions  exist  which  cause  mercury  to  expand  a 
certain  amount,  sentient  beings  have  the  experience 
of  warmth,  but  it  is  not  found  necessary  to  assume 
that  there  is  any  such  thing  as  warmth,  except  when 
the  agencies  that  cause  the  mercury  to  expand  act 
upon  a  sentient  organism. 

According  to  this  view,  then,  temperature  is  repre- 
sented by  air-waves,  in  any  situation  where  no  sen- 
tient beings  are  present.  We  are  not  entitled  to  say 
that  in  such  a  situation  objects  are  either  warm  or 
cold,  because  these  terms  presuppose  a  relation  be- 
tween the  objects  and  a  conscious  being.  If  this  is 
the  case,  it  seems  evident  that  any  attribute  or  quality 
which  exists,  even  though  not  experienced,  must  be 
of  a  kind  that  does  not  presuppose  such  a  relation. 
Thus  if  we  assert  that  a  given  object  has  a  certain 
color  or  size  or  shape  when  not  perceived,  we  take 
for  granted  that  these  qualities  are  essentially  differ- 
ent from  temperature.  The  question  how  cold  a  block 
of  ice  is  when  no  one  touches  it,  or  is  in  any  way 
affected  by  it,  is  apparently  unanswerable  (unless  the 
question  is  meant  to  refer  merely  to  the  effect  of 
the  ice  upon  a  thermometer).  We  commonly  suppose, 
however,  that  a  similar  question  as  to  its  color  or 
its  shape  or  its  size  is  a  different  matter.  We  tend 
to  assume  that  we  can  ascertain  what  these  qualities 
are  '  in  themselves,'  i.e.,  what  they  are  when  they  are 
not  the  objects  of  any  experience. 

When  we  consider  the  facts  in  the  case,  however, 
it  appears  that  these  qualities  are  on  the  same  footing 
with  the  quality  of  temperature.  If  we  ask,  for  ex- 
ample, what  the  size  of  a  given  object  may  be,  we 


THE  PROBLEM  OF  SENSE-PERCEPTION       259 

find  that  the  answer  depends  upon  the  nature  and 
the  condition  of  the  sense-organ  through  which  the 
size  is  experienced.  "  The  interior  of  one's  mouth 
cavity  feels  larger  when  explored  by  the  tongue  than 
when  looked  at.  The  crater  of  a  newly-extracted 
tooth,  and  the  movements  of  a  loose  tooth  in  its  socket, 
feel  quite  monstrous.  A  midge  buzzing  against  the 
drum  of  the  ear  will  often  feel  as  big  as  a  butterfly. ' '  * 
Again,  "  Apply  the  blunt  end  of  a  pencil  to  the  fore- 
head, to  the  lips,  to  the  back  of  the  hand,  to  the  tip 
of  a  finger,  to  the  drum  of  the  ear.  The  resulting 
tactual  sensations  vary  conspicuously  in  extent, 
though  the  areas  of  the  skin  affected  are  throughout 
equal  and  the  surface  with  which  they  are  brought 
in  contact  remains  constant  in  size.  None  of  the 
tactual  sensations  has  any  better  logical  claim  than 
the  others  to  be  identified  with  the  real  extent  either 
of  the  skin  stimulated  or  of  the  surface  applied  to 
it;  and  their  rival  claims  are  mutually  destructive. 
Skin  sensibility  is  also  variable  in  this  respect  from 
one  individual  to  another;  it  is  different  in  the  child 
and  the  adult;  it  is  affected  by  disease  of  the  brain, 
and  by  the  use  of  drugs  such  as  narcotics. ' '  f 

It  is  evident  that  the  question  as  to  size  cannot 
be  answered  merely  by  resort  to  measurement.  If  we 
should  find  by  measurement  that  an  object  is  an 
inch  long,  the  question  recurs,  how  long  is  an  inch? 
Visual  perceptions  and  tactual  perceptions  present 
conflicting  reports,  and  we  seem  unable  to  decide 
which  of  these  reports  is  more  correct  than  the  others. 

*  James,  Psychology,  Vol.  II.,  p.  139. 

f  G.  F.  Stout,  Proceedings  of  the  Aristotelian  Society, 
1903-4,  p.  151. 


2G0  AN  OUTLINE  OF  LOGIC 

In  everyday  life,  it  is  true,  we  accord  pre-eminence 
to  the  deliverances  of  visual  perceptions.  Thus  we 
commonly  say  that  the  cavity  in  a  tooth  feels  bigger 
than  it '  really  '  is.  This,  however,  is  merely  a  matter 
of  convenience.  We  adopt  visual  perception  as  our 
standard,  because  it  plays  so  important  a  part  in 
practical  life.  Our  visual  perceptions  have  indeed 
been  modified  through  association  with  the  tactual 
perceptions  of  the  hands,  but  they  fail  to  harmonize 
with  other  tactual  perceptions,  and  so  these  latter 
are  classed  as  unreal.  But  even  if  we  assume,  for 
the  sake  of  the  argument,  that  vision  is  more  reliable 
than  some  of  the  tactual  perceptions,  our  difficulty 
presents  itself  anew.  The  apparent  size  of  an  object 
varies  with  its  distance  from  the  retina.  In  practice 
the  size  selected  as  the  '  real  '  size  is  usually  the  size 
that  we  see  when  the  object  is  at  such  a  distance 
as  to  enable  us  to  see  both  its  contour  and  a  maximum 
of  detail  within  its  boundaries.  But  this  standard  is 
departed  from  when  the  object  is  placed  under  a 
microscope.  We  then  say  that  the  object  appears 
larger  than  it  really  is,  because  the  object  as  it 
appears  under  the  microscope  is  compared  with  its 
appearance  as  seen  with  the  naked  eye.  In  short, 
we  are  unable  to  justify  the  selection  of  one  visual 
perception  rather  than  another  as  the  perception 
which  gives  us  the  '  real  '  size.  When  we  consider, 
further,  that  a  comparison  of  different  forms  of  ani- 
mals reveals  wide  differences  in  the  structure  of  the 
eye  and  thus  gives  ground  for  the  supposition  that 
there  must  be  wide  differences  in  visual  perception 
as  well,  the  difficulty  becomes  still  more  formidable. 
As  with  temperature,  the  difficulty  is  to  understand 


THE  PROBLEM  OF  SENSE-PERCEPTION      261 

what  is  meant  by  size,  independently  of  all  relations 
to  a  sense-organ.  We  seem  unable  to  determine  what 
the  size  of  anything  is  '  in  itself.'  We  can  at  best 
only  assert  that  an  object  has  a  certain  size  under 
certain  conditions,  such  as  a  certain  specified  type 
of  sense-organ  and  a  certain  fixed  point  of  view. 

A  little  reflection  will  show  that  a  similar  con- 
clusion is  required  with  respect  to  shape.  Apparent 
shapes  vary  quite  as  much  as  apparent  sizes;  and 
the  variations  are  increased  when  we  take  into  ac- 
count the  appearances  of  objects  under  the  micro- 
scope. An  object  which,  when  seen  with  the  unaided 
eye,  appears  to  possess  a  smooth  round  edge,  may 
present  an  extremely  jagged  contour  when  seen 
under  the  microscope,  the  degree  of  roughness 
depending  upon  the  magnifying  powers  of  the 
instrument. 

With  regard  to  attributes  like  colors  and  sounds 
we  arrive  at  the  same  result.  Psychology  teaches  that 
the  psychical  result  of  a  stimulus  affecting  a  sense- 
organ  is  changed  if  other  stimuli  affect  the  same 
sense-organ,  either  at  the  same  time  or  immediately 
before.  This  fact  gives  rise  to  the  phenomena  of 
contrast,  which,  "  although  characterizing  in  a  meas- 
ure all  sense  domains,  and  for  that  matter  all  con- 
scious processes,  are  especially  striking  in  vision. 
Yellow  and  blue  appear  respectively  yellower  and 
bluer,  when  seen  side  by  side,  than  when  seen  apart. 
This  seems  to  be  largely  because  of  the  fact  that 
the  eye  moves  slightly  from  one  to  the  other;  and 
the  eye  fatigued  for  blue  already  has  a  disposition 
to  react  with  the  yellow  after-image.  If  the  part 
of  the  retina  containing  this  yellow  after-image  proc- 


262  AN  OUTLINE  OF  LOGIC 

ess  is  then  exposed  to  the  real  objective  yellow,  the 
power  of  the  stimulus  is  much  enhanced,  and  we  see 
a  deeper,  more  intense  yellow  than  we  otherwise 
should.  This  phenomenon  is  called  successive  con- 
trast. Simultaneous  contrast  is  an  even  more  inter- 
esing  phenomenon,  and  may  be  illustrated  by  putting 
a  small  bit  of  gray  paper  upon  any  colored  field,  and 
then  covering  the  whole  with  thin  white  tissue  paper. 
The  gray  patch,  under  such  conditions,  always  appears 
as  a  color  complementary  to  that  of  the  field,  i.e.,  it 
will  appear  blue,  when  the  field  is  yellow;  yellow, 
when  it  is  blue;  reddish  when  it  is  green,  etc.  .  .  . 
Our  color  sensations  are  dependent,  not  only  upon 
the  color  of  the  objects  immediately  fixated,  but  also 
upon  the  colors  surrounding  it,  and  upon  the  im- 
mediately preceding  stimulation."* 

As  suggested  by  this  quotation,  other  perceptions 
are  likewise  subject  to  the  law  of  contrast.  Notes 
modify  each  other  in  a  chord;  and  the  first  peal  of 
a  bell,  breaking  in  upon  a  previous  silence,  has  a 
more  '  aggressive  '  sound  than  the  second  which  im- 
mediately follows  it.  The  distance  between  the  ob- 
jects whence  the  sound  proceeds  and  the  ear  is  also 
an  important  factor.  It  seems  clear  that  the  question 
as  to  the  '  absolute  '  color  or  sound  of  an  object,  like 
the  question  regarding  '  absolute  '  size  or  shape  or 
temperature,  is  quite  unanswerable.  There  is  always 
implied  a  reference  to  the  condition  of  the  sense-organ 
and  to  the  limitations  imposed  by  a  specific  situation. 
That  is,  we  must  take  account  both  of  the  relation 
of  the  object  to  the  sense-organ  or  perceiving  mind, 
and  of  its  relation  to  other  things,  as  in  color  and 
*  Angell.  Psychology,   p.    112. 


THE  PROBLEM  OF  SENSE-PERCEPTION      263 

sound   contrast.     We  have   apparently  no  standard 
by  which  '  absolute  '  qualities  may  be  determined. 

Primary  and  Secondary  Qualities. — It  was  sug- 
gested, a  few  pages  back,  that  the  difficulty  here  dis- 
cussed finds  a  certain  recognition  on  the  part  of 
physical  science.  Temperature  and  sound,  for  ex- 
ample, are  often  regarded  as  merely  effects  produced 
by  air- waves  and  are  not  supposed  to  exist  in  the 
absence  of  the  appropriate  sense-organs.  Similarly 
color  is  the  effect  produced  by  ether-waves  upon  the 
retina  of  the  eye.  The  ether  is  not  itself  colored, 
but  it  produces  color  by  acting  upon  the  organ  of 
vision.  All  these  sense-qualities,  in  other  words,  are 
made  to  depend  upon  consciousness  and  not  upon 
objects.  Consciousness  is  not  regarded  as  merely  the 
function  of  apprehending  objective  fact,  but  it  be- 
comes the  source  and  origin  of  qualities  which, 
originally  ascribed  to  objects,  have  now  been  trans- 
ferred from  the  realm  of  matter  to  that  of  mind. 
The  growth  of  knowledge  is  characterized  by  a  certain 
tendency  to  despoil  matter,  for  as  mind  becomes  richer 
in  content,  matter  becomes  poorer,  since  matter  is 
invariably  compelled  to  '  pay  the  bill.' 

This  procedure  has  led,  almost  inevitably,  to  the 
grouping  of  qualities  into  two  classes,  the  '  primary  ' 
and  the  '  secondary.'  Primary  qualities  are  those 
which  are  supposed  to  depend  upon  the  object  ex- 
clusively, such  as  shape,  size  and  hardness ;  secondary- 
qualities  are  those  which  depend  upon  the  perceiving 
mind,  such  as  color  and  taste.  Primary  qualities, 
according  to  this  view,  exist  whether  perceived  or  not ; 
secondary  qualities  exist  only  when  they  are  per- 
ceived.    On  this  theory  sense-perception  presents  ob- 


264  AN  OUTLINE  OF  LOGIC 

jects  in  a  way  that  is  partly  true  and  partly  false. 
Our  perceptions  of  the  primary  qualities  are  photo- 
graphic representations  of  the  qualities  that  belong 
to  objects;  whereas  our  perceptions  of  secondary 
qualities  are  merely  symbolic.  The  latter  stand  for 
qualities  in  the  external  world  but  do  not  reproduce 
them  exactly  as  they  are.  As  regards  secondary 
qualities  our  sensations  are  like  blue  goggles  in  that 
they  distort  the  objects  which  they  represent. 

In  view,  however,  of  what  was  said  regarding  size 
and  shape,  it  seems  that  the  distinction  between 
primary  and  secondary  qualities  is  untenable.  This 
traditional  distinction  may  have  no  other  significance 
than  that  it  enables  the  scientist  to  deal  with  his  facts 
in  a  quantitative  way.  Secondary  qualities  can  per- 
haps be  successfully  explained  in  terms  of  primary 
qualities,  as,  e.g.,  when  sound  is  explained  in  terms  of 
air-vibrations,  as  long  as  we  take  for  granted  the 
objective  character  of  the  primary  qualities.  But  if 
we  find  reason  to  doubt  the  validity  of  the  distinction 
between  primary  and  secondary  qualities,  we  have 
less  reason  to  think  that  the  secondary  qualities  alone 
depend  solely  upon  the  mind.  If  the  distinction  must 
be  given  up,  we  may  be  forced  to  choose  between  the 
view  that  all  qualities  depend  solely  upon  the  mind 
and  the  view  that  all  qualities  are  in  some  way  in- 
herent in  objects. 

How  the  problem  involved  in  the  facts  of  sense- 
perception  is  to  be  solved,  it  is  not  the  business  of 
logic  to  inquire.  The  problem  grows  directly  out  of 
the  inquiry  into  the  processes  by  which  our  knowl- 
edge is  built  up,  but  the  consideration  of  the  problem 
must  be  left  to  other  disciplines,  viz.,  the  theory  of 


THE  PROBLEM  OF  SENSE-PERCEPTION      265 

knowledge  and  metaphysics.  That  knowledge  of  some 
sort  is  possible  must  be  assumed  by  logic  before  its 
inquiry  can  begin.  But  reflection  upon  the  methods 
employed  by  knowledge  cannot  avail  to  ascertain  the 
precise  scope  of  knowledge,  or  to  determine  its  ability 
to  discover  the  true  nature  of  the  world  in  which  we 
live. 


EXERCISES 


NOTE 

Many  of  the  following  examples  have  become  common  prop- 
erty among  logicians,  and  so  I  have  not  been  at  great  pains 
to  ascertain  who  should  be  credited  with  them.  It  is  likely 
also  that  some  of  the  references  here  given  do  not  indicate 
the  real  origin.  The  books  upon  which  I  have  drawn  most 
for  material  and  which  are  mentioned  in  an  abbreviated  form 
are  as  follows: 

Aikins,  Principles  of  Logic    (A). 

Creighton,  Introductory  Logic   (C). 

Hibben,  Logic,  Inductive  and  Deductive   (H). 

Jevons,  Lessons  in  Logic,  and  Studies  in  Deductive  Logic-  (J). 

Mellone,  Textbook  of  Logic   (M). 

Whately,  Elements  of  Logic    (W). 

Wilson,  Treatise  on  Logic   (Wilson). 


EXERCISES 
CHAPTER  II 

From  the  following  exercises  select  those  terms  of  which 
the  meaning  seems  most  uncertain,  and  in  each  case  point 
out  different  meanings  that  are  included  under  the  same 
term.  State  which  of  these  alternative  meanings  you  think 
properly  belongs  to  the  term  in  its  present  context : 

1.  We  should  live  according  to  Nature. 

2.  Life  is  real,  life  is  earnest. 

3.  God  is  truth. 

4.  The  wages  of  sin  is  death. 

5.  All  men  have  natural  rights. 

6.  All  men  are  created  free  and  equal. 

7.  Our  Father,  who  art  in  heaven. 

8.  The  world  is  selfish,  and  so  it  cannot  accept  a  gospel 
of  unselfishness. 

9.  The  King  can  do  no  wrong. 

10.  Ours  is  a  government  of  the  people,  by  the  people, 
and  for  the  people. 

11.  England's  rule  of  Ireland  has  been  a  failure. 

12.  The  proprietor  of  a  circus  once  claimed  that  "  people 
like  to  be  humbugged." 

13.  We  should  love  our  neighbors  as  ourselves,  yet  every- 
body loves  his  immediate  relatives  more  than  sti-angers. 

14.  The  fear  of  the  Lord  is  the  beginning  of  wisdom. 

15.  There  is  nothing  either  good  or  bad,  but  thinking 
makes  it  so. 

16.  A  man  tries  to  shoot  a  squirrel  that  is  clinging  to 
a  tree  on  the  side  opposite  to  the  man.     The  man  walks 

269 


270  AN  OUTLINE  OF  LOGIC 

completely  around  the  tree,  but  the  squirrel  always  keeps 
the  trunk  of  the  tree  between  itself  and  the  man.  Did 
the  man  go  around  the  squirrel? 

17.  Which  hen  is  the  mother  of  the  chicken,  the  one  that 
laid  the  egg  or  the  one  that  hatched  it  out  and  takes  care 
of  it?     (A.) 

18.  No  evil  should  be  allowed  that  good  may  come  of  it; 
all  punishment  is  an  evil;  therefore  no  punishment  should 
be  allowed  that  good  may  come  of  it. 

19.  Whatever  is  dictated  by  Nature  is  allowable;  de- 
votedness  to  the  pursuit  of  pleasure  in  youth,  and  to  that 
of  gain  in  old  age,  are  dictated  by  Nature;  therefore  they 
are  allowable.     (W.) 

20.  Avoid  those  who  cause  divisions. 


CHAPTER  III 

1.  Improbable  events  happen  almost  every  day;  events 
which  happen  almost  every  day  are  probable  events;  there- 
fore improbable  events  are  probable  events. 

2.  The  indestructibility  of  matter  is  a  truth  which  we 
are  bound  to  accept  quite  apart  from  experimental  evi- 
dence. It  is  a  necessity  of  our  thinking,  for,  "  It  is 
impossible  to  think  of  something  becoming  nothing,  for 
the  same  reason  that  it  is  impossible  to  think  of  nothing 
becoming  something — the  reason,  namely,  that  nothing  can- 
not become  an  object  of  consciousness.  The  annihilation 
of  matter  is  unthinkable  for  the  same  reason  that  the 
creation  of  matter  is  unthinkable."  (Spencer,  First  Prin- 
ciples, Part  II.,  Chapter  IV.) 

3.  He  who  believes  himself  to  be  always  in  the  right 
in  his  opinion,  lays  claim  to  infallibility;  you  always  be- 
lieve yourself  to  be  in  the  right  in  your  opinion  (for  an 
opinion  that  you  consider  wrong  is  not  your  opinion) ; 
therefore  you  lay  claim  to  infallibility. 


EXERCISES  271 

•» 

4.  No  cat  has  nine  tails,  one  cat  has  one  tail  more  than 
no  cat;  therefore  one  cat  has  ten  tails. 

5.  "A  gentleman  told  me  that  he  had  a  conclusive  argu- 
ment for  opening  the  Harvard  Medical  School  to  women. 
It  was  this :  '  Are  not  women  human  ? ' — which  major 
premise,  of  course,  had  to  be  granted.  '  Then  are  they 
not  entitled  to  all  the  rights  of  humanity?'  My  friend 
said  that  he  had  never  met  any  one  who  could  successfully 
meet  this  reasoning."    (James,  Psychology,  Vol.  II.,  p.  674.) 

6.  Life,  God,  omnipotent  Good,  deny  death,  evil,  sin, 
disease. — Disease,  sin,  evil,  death,  deny  Good,  omnipotent 
God,  Life.  Which  of  the  denials  ...  is  true?  Both  are 
not,  can  not  be  true."  {Science  and  Health,  chapter  on 
Science,  Theology,  Medicine.) 

7.  This  stove  saves  half  the  ordinary  amount  of  fuel; 
therefore  two  such  stoves  would  save  it  all. 

8.  He  who  cannot  possibly  act  otherwise  than  he  does 
has  neither  merit  nor  demerit  in  his  action;  a  liberal  and 
benevolent  man  cannot  possibly  act  otherwise  than  he 
does  in  relieving  the  poor;  therefore  such  a  man  has 
neither  merit  nor  demerit  in  his  action. 

9.  "  By  virtue  of  the  law  that  a  civilized  people  absorbs 
its  neighbors  who  are  in  intellectual  nonage — a  law  which 
is  as  universally  valid  and  as  much  a  law  of  nature  as 
the  law  of  gravity — the  Italian  nature  was  entitled  to  reduce 
to  subjection  the  Greek  states  of  the  East."  (Mommsen, 
History  of  Rome,  Book  V.,  Chapter  VII.;  quoted  by 
Palmer,  Field  of  Ethics,  p.  27.) 

10.  In  going  around  the  world  westward  we  keep  gain- 
ing time,  and  the  whole  trip  would  gain  us  a  full  day; 
therefore  if  we  could  make  the  complete  journey  in  twenty- 
four  hours  it  would  really  take  us  no  time  at  all.     (A.) 

11.  "  No  reason,  however,  can  be  given  why  the  general 
happiness  is  desirable,  except  that  each  person,  so  far 
as  he  believes  it  to  be  attainable,  desires  his  own  happiness. 
This,  however,  being  a  fact,  we  have  not  only  all  the  proof 


272  AN  OUTLINE  OF  LOGIC 

which  the  case  admits  of,  but  all  which  it  is  possible  to 
require,  that  happiness  is  a  good,  that  each  person's  happi- 
ness is  a  good  to  that  person,  and  the  general  happiness, 
therefore,  a  good  to  the  aggregate  of  all  persons."  (Mill, 
Utilitarianism.) 

12.  Revenge,  Robbery,  Adultery,  Infanticide,  etc.,  have 
been  countenanced  by  public  opinion  in  several  countries; 
all  the  crimes  we  know  of  are  Revenge,  Robbery,  Adultery, 
Infanticide,  etc.;  therefore  all  the  crimes  we  know  of  have 
been  countenanced  by  public  opinion  in  several  countries. 
(W.) 

13.  I  am  under  an  obligation  to  do  it;  but  he  who  is 
obliged  has  no  power  of  resistance;  consequently  I  have  no 
choice  about  the  matter. 

14.  A  man  cannot  always  be  right  in  his  opinions,  and 
therefore  we  ought  continually  to  distrust  our  judgments. 

15.  Try  to  formulate  the  divergent  notions  of  force, 
matter,  and  motion  that  are  expressed  or  implied  in  the 
following  extracts: 

"  No  force  without  matter — no  matter  without  force. 
One  is  no  more  possible,  and  no  more  imaginable  by  itself 
than  the  other.  .  .  .  Force  and  matter  are  fundamentally 
the  same  thing,  contemplated  from  different  standpoints. 
In  the  material  world  we  know  of  no  example  of  a  particle 
of  matter  not  endowed  with  force  or  working  by  it.  We 
must  further  admit  on  closer  investigation,  that  matter 
as  such  could  make  no  impression  on  our  sense-organs  or 
minds;  it  can  only  do  this  by  means  of  the  forces  united 
with  or  at  work  within  it.  A  piece  of  lead  held  in  the 
hand  presses  on  it  because  of  the  attractive  force  of  the 
earth  and  so  produces  the  idea  of  weight.  .  .  .  Nothing  can 
prove  to  us  the  real  existence  of  a  force,  except  the 
properties,  changes  and  movements,  which  we  become  con- 
scious of  in  matter,  and  these  we  call  different  '  forces ' 
according  to  the  resemblances  or  differences  in  such  mani- 
festations; any  knowledge  of  them  by  other  ways  is  im- 


EXERCISES  273 

possible.  .  .  .  Force  may  be  defined  as  a  condition  of  activity 
or  a  motion  of  matter  or  of  the  minutest  particles  of  matter 
or  a  capacity  thereof;  yet  more  precisely,  as  an  expression 
for  the  reason  of  a  possible  or  actual  movement.  .  .  . 

"  Motion  must  be  regarded  as  an  eternal  and  inseparable 
property  or  as  a  necessary  condition  of  matter.  Matter 
without  motion  exists  no  more  than  matter  without  force; 
motion  without  matter  exists  as  little  as  force  without 
matter.  Nor  can  motion  be  deduced  from  any  force,  for 
it  is  the  very  essence  of  force  itself,  and  can  therefore  have 
no  origin,  but  must  be  eternal  and  in  all  places.  .  .  .  The 
most  solid  body  owes  its  condition  only  to  the  mutual 
attractive  force  of  its  minutest  particles,  which  continually 
oscillate  or  swing  round  the  so-called  center  of  gravity,  and 
without  which  it  would  at  once  fall  to  pieces.  That  these 
particles  are  never  able  to  attain  a  condition  of  relative 
rest  is  proved  by  the  universally  present  force  of  heat, 
which  is  known  to  be  nothing  more  than  a  mode  of  motion 
and  which,  since  all  bodies  without  exception  contain  heat, 
keep  these  smallest  particles  or  molecules  in  a  state  of 
continual  movement.  .  .  .  Motion  must  therefore  be  regarded 
as  the  primal  condition  or  in  some  measure  as  the  soul  of 
matter."  (Buechner,  Force  and  Matter,  Chapters  on  Force 
and  Matter,  and  Motion.) 

16.  In  the  following  passages,  which  are  intended  to 
prove  that  a  lie  is  never  justifiable,  distinguish  carefully 
between  the  different  meanings  of  "  truth  "  and  "  true,"  and 
substitute  for  these  words  wherever  they  occur: 

(a)  "  Truth  is,  so  to  speak,  the  very  substratum  of  Deity. 
...  As  there  is  no  God  but  the  true  God,  so  without  tnith 
there  is  and  can  be  no  God." 

(b)  "As  Christ  is  Truth,  those  who  are  in  Christ  must 
never  violate  the  truth.  .  .  .  This  would  seem  to  be  explicit 
enough  to  shut  out  the  possibility  of  a  justifiable  lie." 

(c)  "We  cannot  conceive  of  God  as  God,  unless  we 
conceive  of  Him  as  the  true  God,  and  the  God  of  truth. 


274  AN  OUTLINE  OF  LOGIC 

If  there  is  any  falsity  in  him,  he  is  not  the  true  God. 
Truth  is  of  God's  very  nature.  To  admit  in  our  thought 
that  a  lie  is  of  God,  is  to  admit  that  falsity  is  in  him, 
or,  in  other  words,  that  he  is  a  false  god." 

(d)  "A  lie  is  the  opposite  of  truth,  and  a  being  who 
will  lie  stands  opposed  to  God,  who  by  his  very  nature 
cannot  lie.  Hence  he  who  lies  takes  a  stand,  by  that 
very  act,  in  opposition  to  God.  Therefore  if  it  be  nec- 
essary at  any  time  to  lie,  it  is  necessary  to  desert  God 
and  be  in  hostility  to  him  so  long  as  the  necessity  for 
lying  continues."  (Trumbull,  A  Lie  Never  Justifiable; 
quoted  by  Aikins,  Principles  of  Logic,  pp.  25,  26.) 

17.  No  one  desires  evil  knowing  it  to  be  evil;  to  do 
wrong  is  evil;  therefore  no  one  desires  to  do  wrong  save 
through  ignorance. 

18.  Nothing  is  possible  unless  all  the  conditions  of  its 
existence  are  fulfilled;  but  when  all  these  conditions  are 
present,  it  actually  exists;  therefore  whatever  is  possible 
is  actual.     (Mellone.) 

19.  A  small  boy  who  was  reminded  that  he  had  been 
told  to  "  stop  making  that  noise,"  replied  that  he  was  not 
making  that  noise  any  more,  but  another  just  like  it.  What 
ambiguity  is  involved  ha  this  reply? 

20.  '  I  may  fairly  expect  that  one  who  has  received  kind- 
ness from  me  should  protect  me  in  distress;  yet  I  may 
have  reason  to  expect  that  he  will  not.'     (W.)     Explain. 


CHAPTER  IV 

1.  Testimony  is  a  kind  of  evidence  that  is  very  likely  to 
be  false;  the  evidence  on  which  most  men  believe  that  there 
are  pyramids  in  Egypt  is  testimony;  therefore  the  evidence 
on  which  most  men  believe  that  there  are  pyramids  in  Egypt 
is  very  likely  to  be  false.     (W.) 

2.  As  a  thing  is  generally  sold  for  more  than  it  is  worth, 


EXERCISES  275 

or  for  less,  one  of  the  parties  to  an  exchange  commonly  is 
a  loser  by  the  transaction.     (H.) 

3.  Man  is  not  created  by  God,  but  is  the  product  of 
Evolution. 

4.  '  An  honest  man's  the  noblest  work  of  God ' ;  Z  is  an 
honest  man;  therefore,  he  is — what?     (Minto.) 

5.  No  soldiers  should  be  brought  into  the  field  who  are 
not  well  qualified  to  perform  their  part;  none  but  veterans 
are  well  qualified  to  perform  their  part;  therefore  none 
but  veterans  should  be  brought  into  the  field.     (W.) 

6.  "  To  be  up  after  midnight,  and  to  go  to  bed  then,  is 
early;  so  that,  to  go  to  bed  after  midnight  is  to  go  to  bed 
betimes."     (Twelfth  Night,  Act  II.,  Scene  3.) 

7.  Epimenides,  the  Cretan,  says  that  "  all  the  Cretans 
are  liars,"  but  Epimenides  is  himself  a  Cretan;  therefore 
he  is  himself  a  liar.  But  if  he  be  a  liar,  what  he  says  is 
untrue,  and  consequently  the  Cretans  are  veracious;  but 
Epimenides  is  a  Cretan,  and  therefore  what  he  says  is 
true;  hence  the  Cretans  are  liars,  Epimenides  is  himself 
a  liar,  and  what  he  says  is  untrue. 

8.  "  It  [the  sun]  moves  to  the  south  because  of  the 
cold  which  drives  it  into  the  warm  pai*ts  of  the  heavens 
over  Libya."  (Herodotus;  quoted  by  James,  Varieties  of 
Religious  Experience,  p.  496,  note.) 

9.  "  Do  unto  others  as  you  would  have  others  do  unto 
you."  If  I  were  unable  to  answer  the  questions  in  an 
examination,  I  should  want  my  neighbor  to  give  me  assist- 
ance ;  therefore  it  is  my  duty  to  help  this  man  who  is  having 
trouble. 

10.  He  who  is  most  hungry  eats  most;  he  who  eats 
least  is  most  hungry;  therefore  he  who  eats  least  eats 
most.     (Aldrich.) 

11.  "What  is  worth  doing  at  all  is  worth  doing 
well."  Show  how  this  statement  must  be  limited  in  its 
application. 

12.  "  We  are  aware  that  a  considerable  number  of  per- 


276  AN  OUTLINE  OF  LOGIC 

sons  still  cling  to  the  punishment  of  death  for  murder,  on 
the  ground  that  murder  deserves  death.  Murder,  they  say, 
is  a  crime  per  se;  it  transcends  every  other  offense,  not 
in  degree  only,  but  in  essential  turpitude;  and  it  is  there- 
fore right  that  the  murderer  should  be  killed.  This  argu- 
ment we  propose  to  meet  and  combat. 

"  The  first  answer  that  we  make  to  the  foregoing  reason- 
ing is  that  mere  desert  is  not  a  ground  on  which  it  becomes 
us  to  punish.  Were  we  all  visited  "  according  to  our  in- 
iquities," which  of  us  would  survive  to  execute  the  mur- 
derer ?  He  only  that  is  "  without  sin  "  has  a  right  to  "  cast 
the  first  stone"  at  the  offender;  and  who  among  us  can 
pretend  to  be  in  that  position1?  We  must  recollect  that 
in  claiming  to  punish  on  the  ground  of  desert,  we  arraign, 
not  the  act,  but  the  motive.  Now,  which  of  us  would  not 
merit  the  murderer's  doom  if  all  our  motives  could  be 
evidenced  against  us?  Is  there  any  human  being  that  has 
not,  at  some  time  or  other,  entertained  an  unkind,  a  revenge- 
ful, a  malicious,  thought  towards  a  fellow-creature?  And 
is  not  such  a  thought  as  essentially  and  inherently  murder 
as  the  very  act  of  homicide  itself?  .  .  . 

"  We  would  inquire,  secondly,  into  the  rationale  of  this 
argument  about  desert.  Why  does  the  murderer  deserve 
death?  The  answer  will  be,  Because  he  has  deliberately 
taken  human  life.  Then,  of  course,  the  same  guilt  is  per- 
petrated, and  the  same  penalty  incurred,  when  the  law 
deliberately  takes  human  life  in  return.  For  wherein  is 
the  difference?  Both  acts  of  homicide  are  perpetrated  wil- 
fully; and  to  our  mind  the  homicide  of  the  law  is  worse 
than  the  homicide  of  the  assassin,  inasmuch  as  it  is  com- 
mitted in  cold  blood,  and  in  sight  of  day.  Perhaps  it  will 
be  replied  that  the  motive  makes  the  difference.  But  what 
is  the  motive  of  the  law?  Let  it  be  called  what  it  may, 
vindication  of  justice,  infliction  of  desert,  or  what  not,  it 
is  neither  more  nor  less  than  an  intention  to  retaliate  venge- 
ance on  an  evildoer.     And  is  this  a  motive  that  can  be 


EXERCISES  277 

safely  preached  by  a  government  to  a  people?  Will  an 
individual  refrain  from  revenge  when  the  state  asserts  its 
propriety?  If,  as  is  said  by  political  philosophers,  govern- 
ments have  no  rights,  no  powers,  which  are  not  derived  from 
individual  rights  and  powers,  will  not  an  aggrieved  indi- 
vidual say,  '  What  the  state  may  do,  I  may  do/  and  take 
vengeance  accordingly?  We  have  already  shown  that  men 
do  thus  reason;  and  now  we  have  shown  that  if  the  law 
is  right,  they  are  justified  in  doing  so. 

"  Again :  it  is  said  that  '  the  murderer  deserves  death.' 
For  what?  For  his  evil  motive.  But  we  cannot  see 
motive.  The  hearts  of  our  fellow-creatures  are  hidden  from 
us,  and  we  cannot  certainly  ascertain  and  know  even  the 
simplest  of  their  thoughts.  We  may  guess  at  them;  but 
when  we  guess  at  the  motives  of  others,  are  we  not  wrong 
in  nineteen  cases  out  of  twenty?  Before  we  can  be  justi- 
fied in  arraigning  and  punishing  motive,  we  must  show 
that  we  are  able  to  discern  it  accurately,  and  properly  esti- 
mate its  nature  and  its  force.  Nor  is  this  all.  We  must 
be  able  to  estimate  the  strength  of  the  temptation,  too.  The 
man  who  is  strongly  tempted  to  commit  murder,  by  want, 
by  injuries  received,  or  by  great  provocation  of  any  other 
kind,  is  surely  not  so  worthy  of  punishment  as  the  man 
who  is  actuated  by  malignant  hatred  and  unwarranted 
malice.  Now  it  must  be  plain  that  we  cannot  possibly 
judge  in  this  manner,  inasmuch  as  our  faculties  are  not 
sufficiently  clear  and  far-sighted;  and,  such  being  the  case, 
the  endeavor  to  inflict  penalties  upon  evil  motive  is  a  mere 
hypocritical  pretence  and  mockery,  a  presumptuous  usurpa- 
tion of  the  Eternal  prerogative."  {Eclectic  Review,  July, 
1849,  pp.  115-7.) 

13.  In  the  following  three  passages  select  the  abstract 
terms  of  which  the  meaning  seems  doubtful,  and  replace 
with  concrete  terms: 

(a)  There  is  no  life,  truth,  intelligence,  or  substance  in 
matter.    All  is  infinite  Mind  and  its  infinite  manifestation, 


278  AN  OUTLINE  OF  LOGIC 

for  God  is  All  in  all.     Spirit  is  immortal  truth;  matter 
is  mortal  error. 

(b)  Life  is  neither  in  nor  of  matter.  What  is  termed 
matter  is  unknown  to  Spirit,  which  involves  in  itself  all 
Substance,  and  is  Life  eternal.  Matter  is  a  human  concept. 
Life  is  divine  Mind.  Life  is  not  limited.  Death  and 
finiteness  are  unknown  to  Life. 

(c)  If  Good,  or  God,  is  real,  then  evil,  the  opposite  of 
God,  is  unreal.  Then  evil  can  only  seem  real,  by  giving 
reality  to  the  unreal.  The  children  of  God  have  but  one 
Mind.  How  can  Good  lapse  into  evil,  when  God,  the 
Mind  of  man,  never  sins?  {Science  and  Health,  Chapter 
on  Recapitulation.) 

14.  An  idle  man  hates  life,  for  he  kills  time,  and  time 
is  the  stuff  that  life  is  made  of. 

15.  What  is  the  opinion  of  science  expressed  in  the  fol- 
lowing lines?  Show  that  they  may  be  interpreted  in  more 
than  one  way: 

Books!  'tis  a  dull  and  endless  strife: 
Come,  hear  the  woodland  linnet, 
How  sweet  his  music!  on  my  life, 
There's  more  of  wisdom  in  it. 

Sweet  is  the  lore  which  Nature  brings ; 
Our  meddling  intellect 

Mis-shapes  the  beauteous  forms  of  things:— 
We  murder  to  dissect. 

Enough  of  Science  and  of  Art; 

Close  up  those  barren  leaves; 

Come  forth,   and  bring  with  you  a  heart 

That  watches  and  receives. 

(Wordsworth,  The  Tables  Turned.) 

16.  The  whole  is  greater  than  the  part;  we  are  capable 
of  wisdom  and  we  are  part  of  the  world,  therefore  the 
world  is  capable  of  wisdom. 


EXERCISES  279 

17.  A  story  is  not  to  be  believed,  the  reporters  of  which 
give  contradictory  accounts  of  it;  the  story  of  the  life  and 
exploits  of  Bonaparte  is  of  this  description;  therefore  it 
is  not  to  be  believed.     (W.) 

18.  The  cause  of  evil  is  itself  an  evil.  But  that  Chris- 
tianity has  caused  much  evil  in  the  shape  of  wars,  oppres- 
sion, imposture,  fanaticism,  and  persecution  cannot  be 
denied.     (Wilson.) 

19.  Actions  that  benefit  mankind  are  virtuous;  therefore 
it  is  a  virtuous  action  to  till  the  ground.     (J.) 

20.  Repentance  is  a  good  thing;  wicked  men  abound  in 
repentance;  therefore  wicked  men  abound  in  what  is 
good.     (W.) 

21.  "In  a  given  state  of  society  a  certain  number  of 
persons  .  .  .  must  put  an  end  to  their  own  life.  This  is 
the  general  law,  and  the  special  question  as  to  who  shall 
commit  the  crime  depends,  of  course,  upon  special  laws, 
which,  however,  hi  their  total  action,  must  obey  the  large 
social  law  to  which  they  are  all  subordinate.  And  the 
power  of  the  larger  law  is  so  irresistible  that  neither  the 
love  of  life,  nor  the  fear  of  another  world,  can  avail  any- 
thing towards  even  checking  its  operation."  (Buckle,  His- 
tory of  Civilization,  Vol.  I.,  p.  25.) 


CHAPTER  V 

Test  by  obversion  and  conversion: 

1.  When  we  hear  that  all  the  righteous  people  are  happy, 
it  is  hard  to  avoid  exclaiming,  what!  are  all  the  unhappy 
persons  we  see  to  be  thought  unrighteous? 

2.  If  a  man  who  has  been  accustomed  to  enjoy  liberty 
cannot  be  happy  in  the  condition  of  a  slave,  does  it  follow 
that  a  man  who  has  not  been  accustomed  to  liberty  can  be 
happy  as  a  slave? 

3.  Generosity  is  a  virtue,  therefore  selfishness  is  a  vice. 


280  AN  OUTLINE  OF  LOGIC 

4.  In  the  following  arguments  restate  all  propositions 
containing  words  like  "  few,"  "  only,"  or  "  none  but,"  so 
as  to  indicate  the  correct  quality  and  quantity,  and  deter- 
mine whether  the  argument  is  sound  or  unsound.  If  un- 
sound, point  out  the  false  obversion  or  conversion  that  is 
implied : 

(a)  Only  the  virtuous  are  truly  noble;  some  who  are 
called  noble  are  not  virtuous;  therefore  some  who  are 
called  noble  are  not  truly  noble. 

(b)  He  that  is  of  God  heareth  God's  words;  ye  there- 
fore hear  them  not,  because  ye  are  not  of  God.  John 
viii :  47. 

(c)  Warm  countries  alone  produce  wines;  Spain  is  a 
warm  country;  therefore  Spain  produces  wines. 

(d)  None  but  the  wise  are  good;  none  but  the  good  are 
happy;  therefore  none  but  the  wise  are  happy. 

(e)  Few  towns  in  the  United  Kingdom  have  more 
than  300,000  inhabitants;  and  as  all  such  towns 
ought  to  be  represented  by  three  members  of  Parlia- 
ment, it  is  evident  that  few  towns  ought  to  have  three 
representatives. 

(f)  None  but  the  industrious  deserve  to  succeed;  I  de- 
serve to  succeed;  therefore  I  am  industrious. 

(g)  None  but  the  industrious  deserve  to  succeed;  I  am 
industrious;  therefore  I  desei've  to  succeed. 

(h)  Logic  is  indeed  worthy  of  being  cultivated,  if  Aris- 
totle is  to  be  regarded  as  infallible;  but  he  is  not;  therefore 
logic  is  not  worthy  of  being  cultivated.     (W.) 

(i)  He  who  is  content  with  what  he  has  is  truly  rich; 
a  covetous  man  is  not  content  with  what  he  has;  no 
covetous  man  therefore  is  truly  rich.     (W.) 

(j)  Jones  must  succeed  in  the  world,  for  he  is  an  honest 
man,  and  dishonest  people  never  prosper. 

(k)  Only  those  messages  which  are  prepaid  will  be  de- 
livered. This  message  has  been  prepaid;  and  therefore  it 
will  be  delivered.     (H.) 


EXERCISES  281 

(1)  Pious  men  only  are  fit  to  be  ministers  of  religion; 
some  ignorant  men  are  pious;  therefore  ministers  of  re- 
ligion may  be  ignorant  men. 

(m)  Since  the  virtuous  alone  are  happy,  he  must  be 
virtuous  if  he  is  happy,  and  he  must  be  happy  if  he  is 
virtuous. 

(n)  None  but  whites  are  civilized;  the  Hindoos  are  not 
white;  therefore  the  Hindoos  are  not  civilized. 

(o)  None  but  whites  are  civilized;  the  ancient  Germans 
were  white;  therefore  they  were  civilized. 

(p)  None  but  civilized  people  are  white;  the  Gauls  were 
white;  therefore  they  were  civilized.     (Wilson.) 

(q)  If  some  who  are  very  sentimental  are  nevertheless 
not  benevolent,  then  some  who  are  not  benevolent  are  senti- 
mental.    (Wilson.) 

(r)  The  earth's  position  must  be  fixed,  if  the  fixed  stars 
are  seen  at  all  times  in  the  same  situations;  now  the  fixed 
stars  are  not  seen  at  all  times  in  the  same  situations ;  there- 
fore the  earth's  position  is  not  fixed.     (J.) 

(s)  Only  animals  are  sentient  beings;  fishes  are  animals; 
therefore  fishes  are  sentient  beings. 


CHAPTER  VI 

Put  the  following  arguments  into  syllogistic  form,  plac- 
ing the  major  premise  first,  the  minor  premise  second,  and 
the  conclusion  last;  and  test  the  validity  of  the  inference 
by  circles.  Name  the  figure  of  the  syllogism,  and  if  the 
inference  is  invalid,  give  the  name  of  the  fallacy.  Point 
out  the  error  in  quality  or  quantity  to  which  the  fallacy 
is  due :  vyuM, 

1.  All  A  is  B;  no  A  is  C;  therefore  no  C  is  B.    C 

2.  No  A  is  C ;  all  B  is  C ;  therefore  no  A  is  B.  Cm^   ^^ 

3.  Some  A  is  B;  some  C  is  not  B;  therefore  some  A  is 
not  C. 


°i 


A 


282  AN  OUTLINE  OF  LOGIC 


4.  Some  A  is  B;  some  A  is  not  C;  therefore  some  B  is 
not  C. 

5.  All  A  is  C;  some  B  is  not  A;  therefore  some  B  is 
not  C.      c,  "p 

6.  Quibbling  is  not  necessarily  a  ease  of  sophistry;  for 
quibbling  may  be  unintentional,  while  sophistry  always 
implies  the  intention  to  deceive.  -^ 

7.  Honesty  is  not  always  the  best  policy;  for  honesty 
sometimes  means  starvation,  and  what  ends  in  starvation  is 
certainly  not  the  best  policy.  ^> 

\S     8.  The  radical  is  not  always  a  man  of  lofty  motives; 
\V  your  mere  malcontent,  for  "example,  is  often  rather  a  selfish 
^y"      being/  and  every  malcontent  is  oicoflrse  a  radical,/ 

9.  It  does  not  follow  that  a /stickler  for  truth-telling'  need 
o  ^    be /narrow  and  severe) fQuakers,  for  example,  make  a  great 

aK       Point    °£    teuinS    tue    exacf^anJmeral    truthj)  anaTthey  »+yi 
are     often     charitable     enough./    (Sidgwick,     Fallacies,    (/ 

P-242.)         -v^,-  ^  .a      V        -vvi~*V 

M\-  10/  Some  white  men  have  become  Presidents 1 1  no  negroes 
v\a  have  become  Presidents y  therefore  no  negroes  are  white 
-A  J  men.  -p 

11.  It  is  not  true  that  a  man  cannot  do  a  great  work 
without  a  strong  physique ;  (for  the  philosopne'P  Kant  did 
a  great  work)  and/his  physique  was  Wyming  but  strong. ) 

(A.)  7  Pf^^      .  y 

12.^0  one  is  free  who  is  enslaved  by  his  appetitesj^the 
sensualist  is  enslawd^By^is^appetites  J  therefore  no  sen- 


EAL 


sualist  is  free 


13.(That  man  is  independent  of  the  caprices  of  Fortune 
who  places  his  chief  happiness  in  moral  and  intellectual    /s*A 
)  fA«  excellence)  ^A  true  philosopher  is  independent  of  the  ca- 
^fA     prices   of   Fortune}  therefore   a   true   philosopher  is   one 
l4      J     who  places  his  chief  happiness  in  moral  and  intellectual  r^-l- 

excellence.  vSr^ 

\$^      14.  No  men  are  thoroughly  unselfish;  some  women  are;         5^ 
/  <jri  therefore  some  men  at  least  are  not  women.    (A.)  ^^, 

/  -J  1  ^  X.  £.0 

n-p      tp-m    aj-p  £-« 
s-M      %y-Af     M-s    n  -j 


EXERCISES  283 

15(  These  men  give  alms^no  thieves  give  alms^  therefore 
r  (jr       these  men  are  not  thieves. 

a       16.  Some  men  are  not  fools;  all  men  are  fallible;  there- 
fore— what?  nsi~~-is  I-*—  > /*     ->^^-r^-  \ 
\$i     17.  All  eruelmeirare  eowards^no  college  men  are  cruel;/ 
aJ/^j  therefore  no  college  men  are  cowards. 

18(  Whatever  is  given  on  the  evidence/bi  the  senses  is 
*VV.a  fact ))j;he, existence  of  God,  therefore,  is  not  a  fact,  for 

^  I  flrL  ^  *s  n0^  evi^ntto  sense/ 

^         ^,    19.  No    immoral    doctrine    should    be    tolerated;     this 

I    I  Jft  do^frhie  is  not  immoral ;  theref  oreit  may  be  tolerated.^^- 

Vw       i     20.  Free  Trade  is  a  great  boon  to  the  workingman;  for 

^^  _ .  ij?  increases  trade,  and  cfhisy  cheapens  articles  of  ordinary 

«j\7*j      consumption ;^tnis;  gives   a   greater   purchasing   power   to 

^*U    money,  which  is  equivalent  to  a  rise  in  real  wages,  and 

/  any  rise  in  real  wages1  is  a  boon  to  the  workingman.     (C.) 

21.  (Protection  from  pumsmrien,t  is  plainly  due  to  the 
innocent}  therefore,  as(you  mafmalntnat  this  person  ought 
not  be  punishecy  it  appears  thatfyou  are  convinced  of  his 
innocence./   (W.)  p 

22.  The  use  of  ardent  spirits  should  be  prohibited  by 
law,  seeing  that  At  cause^miseryand  crime  J  which  (it  is 
one  of  thecBie^ends  of  law  to  prevent}    (J.) 

23.  An  avaricious  man  is  one  who  desires  more  than  he  AP 
possesses;  a  man  who  desires  more  than  he  possesses  is  £j> 
discontented;  a  discontented  man  is  unhappy;  therefore  an-- AP 
avaricious  man  is  unhappy.     (M.) 

24.  "  '  He  that  accepts  protection  stipulates  obedience  ' ; 
we  have  always  protected  the  Americans;  we  may  there-     m 
fore  subject  them  to  government.    \  ^**~*- ""-v***  .    Ah*    1  ■ 

"  The  less  is  included  in  the  greater.  That  power  which 
can  take  away  life  may  seize  upon  property.  The  parlia- 
ment may  enact  for  America  a  law  of  capital  punishment; 
it  may  therefore  establish  a  mode  and  proportion  of  taxa- 
tion."    (Dr.  Samuel  Johnson,  The  Patriot.) 

25.  "  He  that  denies  the  English  Parliament  the  right  to 


£ 


284  AN  OUTLINE  OF  LOGIC 

taxation,  denies  it  likewise  the  right  of  making  any  other 
laws,  civil  or  criminal;  yet  this  power  over  the  colonies 
was  never  yet  disputed  by  themselves.  They  have  always 
admitted  statutes  for  the  punishment  of  offenses,  and  for 
the  redress  or  prevention  of  inconveniences;  and  the  recep- 
tion of  any  law  draws  after  it,  by  a  chain  which  cannot 
be  broken,  the  unwelcome  necessity  of  submitting  to  taxa- 
tion."    (Johnson,  Taxation  no  Tyranny.) 

26.  The  child  of  Themistocles  governed  his  mother;  she 
governed  her  husband ;  he  governed  Athens ;  Athens,  Greece ; 
and  Greece  the  world;  therefore  the  child  of  Themistocles 
governed  the  world. 

27.  It  sometimes  happens  that  worthy  pursuits  do  not 
conduce  to  material  gain,  for  certainly  philosophical  studies 
deserve  to  be  pursued,  and  yet  they  often  bring  no  pe- 
cuniary reward.     (M.) 

28.  Every  one  desires  happiness;  virtue  is  happiness; 
therefore  every  one  desires  virtue. 

29.  Whenever  it  is  impossible  not  to  sin,  it  is  unjust  to 
punish.  Now  it  is  always  impossible  not  to  sin,  for  all 
that  is  predetermined  is  necessary,  and  all  that  is  foreseen 
is  predetermined,  and  every  event  is  foreseen.  Hence  it  is 
always  unjust  to  punish.     (Leibniz.) 

30.  A  and  B  are  both  equal  to  C;  hence  they  are  equal 
to  each  other. 

31.  Only  those  actions  which  contribute  to  the  welfare 
of  man  are  virtuous;  therefore,  since  this  action  contributes 
to  the  welfare  of  man,  it  must  be  virtuous. 


CHAPTER  VII 

Determine  whether  the  following  arguments  belong  to 
the  type  of  the  hypothetical  syllogism,  the  disjunctive 
syllogism,  or  the  dilemma;  put  the  reasoning  into  proper 
syllogistic  form  wherever  necessary,  and  judge  of  its  valid- 


EXERCISES  285 

ity.    If  the  argument  is  found  to  be  valid  but  not  true, 
point  out  the  error  in  the  premises: 

1.  If  the  earth  were  of  equal  density  throughout,  it 
would  be  about  2^  times  as  dense  as  water;  but  it  is 
about  5!/2  times  as  dense;  therefore  the  earth  must  be  of 
unequal  density.     (J.) 

2.  If  fire  may  be  separated  from  a  flint,  a  property  may 
be  separated  from  its  subject;  but  fire  cannot  be  separated 
from  the  flint;  therefore  a  property  cannot  be  separated 
from  its  subject.     (Wilson.) 

3.  In  order  to  move,  a  body  must  move  either  in  the 
place  where  it  is,  or  in  the  place  where  it  is  not.  But  it 
cannot  move  in  the  place  where  it  is,  since  that  place  is 
already  occupied.  Neither  can  it  move  in  the  place  where 
it  is  not.    Motion  is  therefore  impossible. 

4.  If  peace  at  any  price  is  desirable,  war  is  an  evil; 
and  as  war  is  confessedly  an  evil,  peace  at  any  price  is 
desirable.     (J.) 

5.  If  all  men  were  capable  of  perfection,  some  would 
have  attained  it ;  but  none  having  done  so,  none  are  capable 
of  it.     (M.) 

6.  "If  he  has  not  studied,  he  will  fail  in  the 
examination."  With  this  proposition  as  a  major 
premise,  what  can  be  inferred  if  we  take  as  minor 
premise : 

(a)  He  has  not  studied. 

(b)  He  will  fail. 

(c)  He  will  not  fail. 

(d)  He  has  studied. 

7.  If  men  are  not  likely  to  be  influenced  in  the  perform- 
ance of  a  known  duty  by  taking  an  oath  to  perform  it,  the 
oaths  commonly  administered  are  superfluous;  if  they  are 
likely  to  be  so  influenced,  every  one  should  be  made  to  take 
an  oath  to  behave  rightly  throughout  his  life.  But  one 
or  the  other  of  these  must  be  the  case;  therefore  either 
the  oaths  commonly  administered  are  superfluous,  or  every 


286  AN  OUTLINE  OF  LOGIC 

man  should  be  made  to  take  an  oath  to  behave  rightly 
throughout  his  life.     (W.) 

8.  According  to  the  story  related  of  Protagoras  and 
Euathlus,  "  the  former  undertook  to  teach  the  latter  the 
art  of  pleading,  and  payment  was  to  be  by  results.  When 
Euathlus  won  his  first  cause  he  was  to  pay  Protagoras  an 
honorarium.  It  happened,  however,  that  he  disliked  the 
dusty  atmosphere  of  the  law,  and  cheated  Protagoras  of 
his  fee  by  refusing  to  become  a  pleader.  Whereupon  Pro- 
tagoras sued  him,  considering  that  should  the  court  award 
the  money  to  himself  it  would  be  his;  while  even  if  the 
court  gave  a  verdict  for  Euathlus  he  would  still  have  the 
money,  which  Euathlus  would  then  be  bound  to  pay  to 
him  in  virtue  of  the  agreement.  He  triumphantly  told 
Euathlus  that  he  would  have  to  pay  in  either  case.  But 
Euathlus  said,  No.  If  I  win  this  cause,  the  judges  will 
have  decided  that  I  need  not  pay  the  money.  If  I  lose  it, 
I  shall  have  no  obligation  under  our  agreement  to  pay." 
(MacLeane,  Reason,  Thought  and  Language,  p.  470.)  Dis- 
cuss this. 

9.  Protective  laws  should  be  abolished,  for  they  are  in- 
jurious if  they  produce  scarcity,  and  they  are  useless  if 
they  do  not.     (J.) 

10.  If  transportation  is  not  felt  as  a  severe  punishment 
it  is  in  itself  ill  suited  to  the  prevention  of  crime;  if  it  is 
so  felt,  much  of  its  severity  is  wasted,  from  its  taking  place 
at  too  great  a  distance  to  affect  the  feelings,  or  even  come 
to  the  knowledge,  of  most  of  those  whom  it  is  designed  to 
deter;  but  one  or  other  of  these  must  be  the  case;  therefore 
transportation  is  not  calculated  to  answer  the  purpose  of 
preventing  crime.     (W.) 

11.  When  the  Caliph  Omar  burned  the  Alexandrian  li- 
brary, he  is  said  to  have  justified  himself  by  saying  that 
if  the  books  in  the  library  contained  the  same  doctrines 
as  the  Koran,  they  were  unnecessary,  while  if  they  con- 
tained  doctrines   at  variance  with  the  Koran   they   were 


EXERCISES  287 

evil ;  and  since  one  or  the  other  must  be  true,  the  books  were 
either  unnecessary  or  evil. 

12.  If  education  is  popular,  compulsion  is  unnecessary; 
if  unpopular,  compulsion  will  not  be  tolerated.     (J.) 

13.  No  honest  man  can  advocate  a  change  in  the  creed 
of  his  church;  for  he  must  either  believe  it  or  not  believe 
it,  and  if  he  believes  it  he  cannot  honestly  help  to  change 
it,  while  if  he  does  not  believe  it  he  cannot  honestly 
belong  to  the  church  at  all.     (A.) 

14.  "  An  abundant  stream  divides  two  limits  of  one  prop- 
erty .  .  .  and  over  this  stream  stood  a  bridge;  and  at  the 
head  of  it  a  gallows,  over  which  were  appointed  four 
judges  to  decide  according  to  the  law  established  by  the 
lord  of  the  stream,  the  bridge  and  the  territory.  The  law 
ran  in  this  wise :  '  If  any  one  shall  pass  over  this  bridge 
from  one  side  to  the  other,  he  must  first  swear  as  to  whence 
he  comes  and  on  what  business  he  is  bound,  and  if  he  swear 
truly  he  must  be  allowed  to  go;  but  if  he  swear  falsely  he 
shall  on  that  account  die  by  hanging  on  the  gallows  which 
is  there;  and  that  without  remission  whatever.'  This  law 
and  its  stern  conditions  being  known,  many  went  over; 
and  as  soon  as  it  was  perceived  that  they  swore  truly,  the 
judges  allowed  them  to  pass  freely.  It  happened,  however, 
that  on  swearing  one  man,  he  took  the  oath  and  declared 
that  he  was  going  to  die  on  that  gallows,  and  that  he  had 
no  other  business.  The  judges  consulted  the  terms  of  the 
oath,  and  said :  '  If  we  allow  that  man  to  go  free,  he  has 
sworn  falsely,  and  according  to  the  law  he  ought  to  die; 
and  if  we  hang  him,  the  oath  that  he  was  going  to  hang 
on  that  gallows  was  true,  and  according  to  the  same  law 
he  ought  to  be  free. ' "  (From  Bon  Quixote,  quoted  by 
Lafleur,  Illustrations  of  Logic,  No.  216.)  Is  there  any  way 
out  of  this  dilemma1? 

15.  "  This  is  either  A  or  B ;  it  is  not  B ;  therefore  it  is 
A."  In  a  similar  way  we  may  reason:  It  is  either  raining 
or  not  raining;  it  is  not  raining;  therefore  it  is  raining. 


288  AN  OUTLINE  OF  LOGIC 


CHAPTER  VIII 

Complete  the  following  arguments  and  state  in  correct 
syllogistic  form: 

1.  Blessed  are  the  meek,  for  they  shall  inherit  the  earth. 

2.  This  man  does  not  have  a  good  record  in  his  studies, 
and  is  therefore  not  eligible. 

3.  A  dog  is  not  rational,  for  he  is  not  human. 

4.  He  must  be  a  strong  man,  for  he  is  on  the  crew. 

5.  He  must  be  a  lawyer,  for  none  but  lawyers  are  ad- 
mitted. 

6.  Some  insane  people  are  clever,  for  some  geniuses  are 
insane. 

7.  He  is  not  a  gentleman,  for  no  gentleman  would  do 
such  a  thing. 

8.  A  military  man  may  become  President,  for  Grant 
became  President. 

9.  Only  the  good  are  fit  to  die,  therefore  capital  punish- 
ment is  wrong. 

10.  You  must  have  come  on  business,  for  the  card  says, 
"  None  admitted  except  on  business." 

11.  Discuss  the  following  arguments,  point  out  the 
tacit  assumptions  wherever  they  occur,  and  consider 
whether  the  assumption  is  permissible.  Put  the  argu- 
ment into  syllogistic  form  wherever  this  may  readily  be 
done: 

(a)  "  We  are  not  inclined  to  ascribe  much  practical  value 
to  that  analysis  of  the  inductive  method  which  Bacon  has 
given  in  the  second  book  of  the  Novum  Organum.  It  is, 
indeed,  an  elaborate  and  correct  analysis.  But  it  is  an 
analysis  of  that  which  we  are  all  doing  from  morning  to 
night,  and  which  we  continue  to  do  even  in  our  dreams." 
(Macaulay.) 

(b)  A  classical  education  is  worthless,  for  we  make  no 
use  of  the  ancient  languages  in  later  life. 


EXERCISES  289 

(e)  For  forms  of  government  let  fools  contest; 
Whate'er  is  best  administered  is  best; 
For  modes  of  faith  let  graceless  zealots  fight; 
His  can't  be  wrong  whose  life  is  in  the  right. 

(Pope,  Essay  on  Man,  Epistle  III., 

(d)  Written  examinations  are  not  an  absolutely  fair 
test  of  a  student's  scholarship — much  less  of  his  industry 
and  intelligence.  It  is  therefore  wrong  to  base  his  grade 
upon  them.     (A.) 

(e)  "An  opinion  as  to  the  constitutionality  of  the  li- 
censed saloon: 

"  The  preamble  to  the  Constitution  of  the  United  States 
is: 

" '  We,  the  people  of  the  United  States,  in  order  to  form 
a  more  perfect  union,  to  establish  justice,  insure  domestic 
tranquillity,  provide  for  the  common  defense,  promote  the 
general  welfare,  and  secure  the  blessings  of  liberty  to  our- 
selves and  our  posterity,  do  ordain  and  establish  this  Con- 
stitution for  the  United  States  of  America.' 

"  I  am  not  able  to  find  that  a  more  perfect  union  was 
ever  formed  or  justice  established  by  the  aid  of  the  saloon. 

"  Not  a  single  case  of  domestic  tranquillity  that  this  in- 
stitution has  insured  appears. 

"  The  common  defense  has  not  been  provided  for,  nor 
the  general  welfare  promoted. 

"  The  blessings  of  liberty  are  endangered  rather  than 
secured. 

"  I  find  the  saloon  has  absolutely  and  completely  failed 
to  promote  the  intent  and  purpose  of  our  fundamental 
law  and  I  therefore  declare  that,  in  my  opinion,  the  saloon 
is  unconstitutional,  is  a  menace  to  the  public  health  and 
safety  and  has  no  right  as  a  government-protected  in- 
stitution to  exist. 

"If  allowed  to  operate  it  will  jeopardize  the  very  life 
of  the  republic. 


290  AN  OUTLINE  OF  LOGIC 

"  If  this  opinion  is  sustained  by  the  voters  the  licensed 
saloon  must  cease  to  be.    Will  you  help  ?  " 

(f)  If  it  is  fated  that  you  die,  you  will  die  whether 
you  call  in  a  doctor  or  not,  and  if  it  is  fated  that  you 
will  recover,  you  will  recover  whether  you  call  in  a  doctor 
or  not.  But  it  must  be  fated  either  that  you  die  or  that 
you  recover.  Therefore,  you  will  either  die  or  recover, 
whether  you  call  in  a  doctor  or  not. 

(g)  Slavery  is  an  outrage  upon  the  inalienable  rights  of 
man.  It  operates,  wherever  it  exists,  as  a  means  of  cor- 
ruption and  degeneracy  to  the  social  and  political  condition 
of  mankind.  Hence,  as  citizens,  as  Christians,  and  as  phil- 
anthropists, we  are  called  upon  to  labor  for  the  promotion 
of  its  immediate  abolition.     (Wilson.) 

(h)  I  have  shown,  gentlemen,  that  it  is  the  natural  right 
of  all  God's  creatures  to  be  free.  I  have  shown  that  a 
people  having  the  same  tongue,  historic  recollections,  and 
associations,  conveniently  situated,  and  existing  in  sufficient 
numbers  for  the  purpose,  are  entitled  to  a  distinct  national 
existence;  and  I  claim,  therefore,  not  only  the  sympathy 
of  Americans  for  my  poor  and  oppressed  Hungary,  which 
I  know  that  I  shall  have,  but  also  their  intervention  as  a 
nation,  and  their  generous  liberality  in  furnishing  the 
material  aid  necessary  to  enable  us  to  carry  on  our 
struggle,  and  secure  our  independence  of  Austrian  rule 
and  despotism.     (Wilson.) 

(i)  "  That  they  who  form  a  settlement  by  a  lawful  char- 
ter, having  committed  no  crime,  forfeit  no  privileges,  will 
be  readily  confessed;  but  what  they  do  not  forfeit  by  any 
judicial  sentence,  they  may  lose  by  natural  effects.  As 
a  man  can  be  in  but  one  place  at  once,  he  cannot  have 
the  advantages  of  multiplied  residence.  He  that  will  enjoy 
the  brightness  of  sunshine  must  quit  the  coolness  of  the 
shade.  He  who  goes  voluntarily  to  America,  cannot  com- 
plain of  losing  what  he  leaves  in  Europe.  He  perhaps 
had  a  right  to  vote  for  a  knight  or  burgess;  by  crossing 


EXERCISES  291 

the  Atlantic  he  has  not  nullified  his  right;  but  he  has  made 
its  exertion  no  longer  possible.  By  his  own  choice  he  has 
left  a  country  where  he  had  a  vote  and  little  property  for 
another  where  he  has  great  property,  but  no  vote.  But 
as  this  preference  was  deliberate  and  unconstrained,  he  is 
still  concerned  in  the  government  of  himself;  he  has  re- 
duced himself  from  a  voter  to  one  of  the  innumerable 
multitude  that  have  no  vote.  He  has  truly  ceded  his  right, 
but  he  still  is  governed  by  his  own  consent."  (Johnson, 
Taxation  no  Tyranny.) 

(j)  "  The  railroads  have  usually  acted  upon  the  apparent 
assumption  that  it  is  none  of  the  public's  business  whether 
they  are  overcapitalized  or  not.  It  remained  for  the  counsel 
for  the  N.  and  N.  railroad,  a  road  notorious  for  its  stock 
watering  operations,  publicly  to  declare — in  the  form  of  a 
question,  it  is  true,  but  none  the  less  bluntly — the  railroad 
position.  If  the  N.  and  N.  'charges  reasonable  rates/ 
demands  its  counsel,  '  what  is  it  to  the  public  whether  its 
capitalization  be  high  or  low?'"  (From  an  editorial.) 
What  assumption  is  involved  in  this  question? 

(k)  Whoever  refuses  to  believe  hi  the  inspiration  of  the 
Bible  makes  the  Most  High  a  deceiver;  for  has  he  not  told 
us  that  '  All  Scripture  is  given  by  inspiration  of  God '  ? 

(1)  "As  to  falsifying  to  a  sick  or  dying  man,  he 
[Dorner]  says  'we  over-estimate  the  value  of  human  life, 
and,  besides,  in  a  measure  usurp  the  place  of  Providence, 
when  we  believe  we  may  save  it  by  committing  sin.' " 

"It  is  a  physician's  duty  to  conceal  from  a  patient  his 
sense  of  the  grave  dangers  disclosed  to  his  professional 
eye,  and  which  he  is  endeavoring  to  meet  successfully.  And 
in  well-nigh  every  case  it  is  possible  for  him  to  give  truth- 
ful answers  that  will  conceal  from  the  patient  what  he 
ought  to  conceal;  for  the  best  physicians  do  not  know  the 
future,  and  his  professional  guesses  are  not  to  be  put 
forward  as  if  they  were  assured  certitudes."  (From  Trum- 
bull's Lie  Never  Justifiable;  quoted  by  Aikins,  p.  471.) 


292  AN  OUTLINE  OF  LOGIC 

(m)  From  an  argument  against  prohibition :  "  In  less 
than  a  decade  the  whole  face  of  the  world  is  changed.  It 
is  now  a  sort  of  treason  to  challenge  any  dogmas  of  social 
policy  that  have  obtained  a  large  following,  especially  if 
they  plead  morality  and  the  interests  of  the  workingman 
as  their  justification.  .  .  .  The  teetotalers  have  increased  in 
number  and  in  power  so  largely  that  newspapers  are  afraid 
to  offend  them.  In  these  matters  and  in  others  we  have 
lost  our  reason.  The  world  is  a  melee  of  special  constables, 
each  bent  upon  getting  his  own  fad  enforced  at  the  point 
of  the  truncheon.  The  police  magistrate  flogs  the  children 
to  school.  The  law  is  invoked  to  take  away  the  grocers' 
wine  and  beer  licenses,  and  otherwise  to  interfere  with 
the  supply  of  what  is  as  much  a  necessary  of  civilized 
life  as  tea;  and  the  scholar  at  his  desk  begins  to  fear  that 
the  law  will  shortly  declare  that  he  must  not  read  Athenaeus, 
Swedenborg,  or  Goethe,  and  will  kindly  send  the  policeman 
to  expurgate  his  library  for  him.  ...  It  never  seems  to 
occur  to  these  intrusive  persons  that  it  is  they  who  are 
the  sinners.  .  .  .  The  rights  of  divergent  opinions?  Justice? 
Those  things  are  obsolescent."  (Contemp.  Review,  Vol.  30, 
p.  455.) 

(n)  Summary  of  an  argument  on  the  question,  Is  Pro- 
hibition a  wise  policy: 

"  There  exists,  then,  a  business  in  this  country  which 
can  be  carried  on  only  by  men  whose  moral  character  is 
at  least  so  low  that  they  cannot  be  expected  to  obey  the 
law;  a  business  which  injures  the  country  more  than  the 
most  stringent  prohibition  of  imports,  or  the  most  un- 
restricted free  trade  could ;  a  business  which  produces  more 
distress,  destroys  more  property,  happiness,  and  life,  than 
all  other  things  known ;  a  business  which  injures  the  coun- 
try every  year  more  than  our  civil  war  did  in  four  years; 
a  business  that  produces  four-fifths  of  all  the  robberies, 
thefts,  murders,  and  other  crimes  in  the  land;  a  business 
which  does  the  nation  and  the  world  more  harm  than  war, 


EXERCISES  293 

famine,  and  pestilence  combined;  a  business  wliicb  stands 
against  all  material,  intellectual,  and  spiritual  progress. 

"  I  am  asked  whether  the  policy  of  making  that  business 
criminal  is  wise?  Most  assuredly,  yes.  If  that  be  not 
true,  where  is  the  wisdom  of  prohibiting  anything?  "  (North 
American  Review,  Vol.  147,  p.  149.) 

(o)  "  The  punishment  of  death  is  unquestionably  the 
most  powerful  deterrent,  the  most  effectual  preventive,  that 
can  be  applied.  Human  nature  teaches  this  fact.  An  in- 
stinct that  outruns  all  reasoning,  a  dreadful  horror  that 
overcomes  all  other  sentiments,  works  in  us  all  when  we 
contemplate  it.  .  .  . 

"  It  has  been  found,  by  the  experience  of  many  nations 
and  many  ages,  that  death  alone  impressed  the  imagination 
of  the  people,  and  alone  carried  so  vivid  a  horror,  as  to 
check  the  malignant  passions  and  the  deadly  hand  of  the 
murderer. 

"  It  has  been  sometimes  objected  that  the  facts  do  not 
bear  out  this  assertion;  that  where  the  capital  penalty  was 
abolished,  the  crime  of  murder  did  not  increase;  that  as 
its  abolition  in  England  as  a  punishment  for  theft  and 
other  lesser  crimes  did  not  result  in  an  increase  of  those, 
the  same  is  found  to  be  the  consequence  of  total  abolition. 
The  space  allowed  me  here  does  not  permit  a  discussion  of 
the  statistics  collected  on  this  question.  Suffice  it  to  say, 
that  the  results,  as  shown  from  the  reliable  records,  do  not 
sustain  so  paradoxical  a  proposition.  It  would  be  in  direct 
contradiction  to  the  ineradicable  instincts  of  humanity  if 
it  were  so.  The  loss  of  life  is  universally  and  instinctively 
dreaded  beyond  all  other  calamities  by  all  classes  of  men — 
the  rich  and  poor,  the  upright  and  vicious,  the  learned  and 
ignorant  alike;  it  is  incredible  that  its  certain  infliction  as 
the  inevitable  consequence  of  an  illegal  act  would  not  have 
the  supremest  influence  in  preventing  that  act."  (North 
American  Review,  Vol.  150,  p.  545-6.) 

(p)  I  will  not  do  this  act,  because  it  is  unjust;  I  know 


294  AN  OUTLINE  OF  LOGIC 

that  it  is  unjust,  because  my  conscience  tells  me  so,  and 
my  conscience  tells  me  so,  because  the  act  is  wrong. 
(Fowler.) 

(q)  "  Mr.  Gladstone,  however,  commits  himself  to  the 
principle  that  '  all  protection  is  morally  bad.'  If  this  has 
been  his  belief  ever  since  he  became  an  advocate  of  free 
trade,  his  conscience  must  have  received  many  and  severe 
wounds,  as  session  after  session,  while  Chancellor  of  the 
Exchequer,  he  carried  through  Parliament  a  bounty — may 
I  not  say  a  direct  protection? — of  £180,000  to  a  line  of 
steamers  running  between  England  and  the  United  States — 
a  protection  that  began  six  years  before  free  trade  was 
proclaimed,  and  was  continued  nearly  twenty  years  after." 
(North  American  Review,  January,  1890;  quoted  by  Hyslop, 
p.  395.) 

CHAPTER  X 

Analyze  the  following  arguments,  in  order  to  determine 
the  method  involved,  and  to  discover,  if  possible,  ground 
for  a  "  reasonable  "  doubt : 

1.  Any  one  who  examines  the  records  will  soon  find  out 
for  himself  that  those  students  who  "  scatter  "  most  in  their 
choice  of  studies  are  those  who  accomplish  least  in  any 
of  them;  and  when  he  sees  this  he  ought  to  realize  the 
harm  that  can  be  done  by  a  system  of  absolutely  free 
electives.     (A.) 

2.  "  Our  correspondent  should  find  solace  in  the  thought 
that  vaccination,  while  giving  no  protection,  may  leave  in 
its  trail  consumption,  scrofula,  cancer  and  other  unexpected 
things,  which  very  things  bring  additional  business  for 
certain  doctors.  These  vaccinators  are  not  so  prehistoric 
as  they  may  appear."  {Life,  June  11,  1908.)  In  what 
way  would  this  statement  have  to  be  proved? 

3.  "  It  does  not  follow  that  an  institution  is  good  because 
a  country  has  prospered  under  it,  nor  bad  because  a  coun- 


EXERCISES  295 

try  in  which  it  exists  is  not  prosperous.  It  does  not  even 
follow  that  institutions  to  be  found  in  all  prosperous  coun- 
tries, and  not  to  be  found  in  backward  countries,  are  there- 
fore beneficial.  For  this  at  various  times  might  confidently 
have  been  asserted  of  slavery,  of  polygamy,  of  aristocracy, 
of  established  churches;  and  it  may  still  be  asserted  of 
public  debts,  of  private  property  in  land,  of  pauperism, 
and  of  the  existence  of  distinctly  vicious  or  criminal  classes." 
(Henry  George,  quoted  by  Creighton,  p.  377.)  What  seems 
to  be  the  correct  inference? 

4.  "  In  Sweden  the  population  and  the  smallpox  mor- 
tality have  both  been  known  year  by  year  since  1774. 
Before  vaccination  the  mortality  from  smallpox  for  thirty 
years  averaged  2,045  per  million.  With  permissive  vaccina- 
tion from  1802  to  1816  it  was  reduced  to  480;  during 
seventy-seven  years  of  compulsory  vaccination  the  mor- 
tality averaged  155  per  million;  and  for  ten  years  ending 
1894  it  has  been  down  to  2  per  million.  .  .  . 

"  If  we  compare  the  rate  of  smallpox  mortality  in  the 
different  countries,  we  see  an  enormous  difference  between 
the  well  vaccinated  and  the  badly  vaccinated  populations. 
Here  is  a  table,  given  by  Dr.  Edwardes,  of  the  mortality 
rates  per  million  in  the  five  years  1889  to  1893: 

Smallpox  mortality 
per  million. 

Germany   2.3 

England  and  Wales 13.6 

Chief  French  towns 147.6 

Italy 180.8 

Belgium    253 

Austria    313 

Spain    638 

Russia,   3    years   only,   including 

Asiatic  Russia  836 

In  Germany,  vaccination  and  revaccination  are  both  com- 
pulsory.   In  the  other  countries  revaccination  was,  at  that 


296  AN  OUTLINE  OF  LOGIC 

time  at  least,  nowhere  enforced."    (Edinburgh  Eeview,  Vol. 
1S9,  pp.  350-2.) 

5.  HOW  TO  NAME  CHILDREN" 

There  are  some  things  which  we  cannot  reason  out.  Science 
fails  to  disclose  the  reason  why  the  cyclone,  in  its  semi- 
elliptical  whirl  moves  from  the  right  to  the  left  in  the 
Northern  hemisphere,  and  from  the  left  to  the  right  in 
the  Southern  half  of  the  globe;  and  so,  too,  some  unknown 
force  directs  the  spiral  course  of  the  creeping  vine.  May 
there  not  be  some  subtle  forces  directing  the  fate  of  men? 
Do  natural  laws  govern  only  the  movement  of  the  winds 
or  the  growth  of  plants?  May  not  a  name  bestowed  upon 
the  helpless  infant  produce  effects,  and  become  "One  of 
the  few,  the  immortal  names  that  were  not  born  to  die  "  ? 

Our  first  parents  and  the  prominent  persons  spoken  of 
in  Holy  "Writ  seem  to  have  had  but  one  name :  Adam,  Eve, 
Cain,  Abel,  Moses,  Aaron,  and  Joshua.  But,  passing  with- 
out notice  the  intervening  ages  and  coming  down  to  our 
own  times  and  confining  ourselves  particularly  to  our  own 
country,  if  we  examine  the  names  of  our  great  men  we 
will  be  surprised  at  the  preponderance  of  single-named 
(meaning  but  one  name  in  addition  to  the  surname)  per- 
sons. 

Let  us  go  to  the  Revolution.  Take  the  signers  of  the 
Declaration  of  Independence.  First,  we  find  a  committee 
to  draft  it.  They  were  Jefferson,  Adams,  Franklin,  Sher- 
man, and  Livingston.  None  of  these  had  middle  names 
except  Livingston.  Of  those  who  signed  the  Declaration, 
on  the  part  of  the  States,  .  .  .  there  were  only  three  who 
had  more  than  one  name. 

"  In  1786  there  was  a  commercial  convention  called  to 
meet  at  Annapolis  to  consider  the  commercial  relations  of 
New  York,  Delaware,  New  Jersey,  Pennsylvania,  and  Vir- 
ginia. Not  a  solitary  delegate  to  that  convention  had  a 
middle  name. 


EXERCISES  297 

"In  1787  a  convention  was  held  to  revise  the  Constitu- 
tion, and  out  of  the  fifty-six  delegates  to  this  convention 
there  were  only  five  with  more  than  one  name. 

"  Of  the  forty-eight  who  signed  the  Articles  of  Confedera- 
tion on  the  ninth  of  July,  1788,  only  four  had  more  than 
one  name.  Of  the  thirty-six  speakers  of  the  House  during 
the  first  half  century  of  the  nation's  existence,  only  twelve 
had  more  than  one  name.  Of  the  five  Chief  Justices  during 
the  same  period  none  had  more  than  one  name.  ...  Of 
the  thirty-one  Associate  Justices  during  the  same  period 
only  five  had  more  than  one  name.  Of  the  eighteen  Secre- 
taries of  State  only  two  had  middle  names;  of  the  eighteen 
Secretaries  of  the  Treasury  only  eight.  Of  the  twenty-six 
Secretaries  of  War,  only  nine;  of  the  twenty-one  Secre- 
taries of  the  Navy,  only  eight. 

"  We  have  had  twenty-two  Presidents  during  our  national 
existence.  Washington,  Adams,  Jefferson,  Madison,  Monroe, 
Jackson,  Van  Buren,  Tyler,  Fillmore,  Pierce,  Buchanan, 
Lincoln,  Johnson,  and  Cleveland  all  entered  into  office  with- 
out the  unnecessary  luggage  of  a  middle  name.  These  sum 
up  fifteen  out  of  the  twenty-two,  and  all  the  '  two-termers ' 
are  in  the  list  except  one  (U.  S.  Grant).  .  .  . 

"Is  there  not  something  in  a  name?  Must  not  there  be 
some  influence,  which  we  know  not  of,  which,  under  the 
operation  of  cause  and  effect,  produces  such  results  as  are 
cited  above?  It  is  true  that  there  are  instances  of  great 
men  whose  names  are  long  and  whose  achievements  are 
famous,  but  are  they  not  few  compared  with  the  number 
of  great  men  with  single  names'?"  (North  American  Re- 
view, Vol.  146,  p.  580-1.) 

6.  "  It  can  easily  be  proved  that  epidemics  of  smallpox 
come  and  go  like  all  other  epidemics,  and  that  neither 
in  intensity  nor  in  duration  were  they  more  formidable 
centuries  ago  than  they  have  been  since  the  use  of  vaccine 
virus  was  introduced  into  the  medical  art.  The  annals 
of  Iceland  show  that  hundreds  of  years  before  vaccination 


298  AN  OUTLINE  OF  LOGIC 

was  heard  of,  that  island  was  wont  to  enjoy  intervals  of 
exemption  from  the  scourge — intervals  of  several  decades 
in  succession.  If  modern  communities  have  similar  inter- 
vals of  exemption,  it  is  a  fallacy  to  credit  their  good 
fortune  to  the  practice  of  vaccination."  (North  American 
Review,  Vol.  134,  p.  1G3.)  Against  what  fallacy  is  this 
last  sentence  intended  as  a  warning? 

7.  "  The  most  generally  received  theory  [as  to  the  origin 
of  animal  coloration]  undoubtedly  is  that  brilliancy  and 
variety  of  color  are  due  to  the  direct  action  of  light  and 
heat;  a  theory  no  doubt  derived  from  the  abundance  of 
bright-colored  birds,  insects,  and  flowers  which  are  brought 
from  tropical  regions.  There  are,  however,  two  strong  argu- 
ments against  this  theory.  .  .  .  Bright  coloration  is  wanting 
in  desert  animals,  yet  here  heat  and  light  are  both  at  a 
maximum,  and  if  these  alone  were  the  agents  in  the  pro- 
duction of  color,  desert  animals  should  be  the  most  brilliant. 
Again,  all  naturalists  who  have  lived  in  tropical  regions 
know  that  the  proportion  of  bright  to  dull-colored  species 
is  little  if  any  greater  there  than  in  the  temperate  zone, 
while  there  are  many  tropical  groups  in  which  bright 
colors  are  almost  entirely  unknown.  .  .  .  Again,  there  are 
many  families  of  birds  which  spread  over  the  whole  world, 
temperate  and  tropical,  and  among  these  the  tropical  species 
rarely  present  any  exceptional  brilliancy  of  color.  .  .  . 
The  same  general  facts  are  found  to  prevail  among  insects. 
Although  tropical  insects  present  some  of  the  most  gorgeous 
coloration  in  the  whole  realm  of  nature,  yet  there  are  thou- 
sands and  tens  of  thousands  of  species  which  are  as  dull 
colored  as  any  in  our  cloudy  land.  .  .  .  The  various  facts 
which  have  now  been  briefly  noticed  are  sufficient  to  indicate 
that  the  light  and  heat  of  the  sun  are  not  the  direct  causes 
of  the  colors  of  animals,  although  they  may  favor  the  pro- 
duction of  color,  when,  as  in  tropical  regions,  the  persistent 
high  temperature  favors  the  development  of  the  maximum  of 
life."     (Wallace,  Darwinism,  pp.  193-5,  quoted  by  Welton, 


EXERCISES  299 

Logical  Bases  of  Education,  p.  277.)     Consider  this  argu- 
ment from  the  point  of  view  of  the  Methods. 

8.  We  all  drank  the  water  and  none  of  us  got  sick; 
so  this  outcry  about  the  danger  of  typhoid  is  all  nonsense. 
(A.) 

9.  "  Innumerable  statistics  have  been  brought  forward  by 
those  favorable  to  the  law  [of  Prohibition,  in  Kansas], 
to  prove  that  it  has  had  a  most  beneficial  effect  on  the 
social  and  moral  condition  of  the  people.  But  it  is  an 
open  question  how  far  the  small  amount  of  poverty  in 
the  State  and  the  reduction  of  crime  are  due  to  prohibition. 
I  have  no  wish  to  minimize  the  actual  good  accomplished 
by  the  law,  but  it  can  serve  no  useful  end  to  claim  for  it 
benefits  that  are  produced  by  other  causes.  Kansas  is  a 
new  settlement,  and  its  surroundings  and  circumstances  are 
such  that  we  might  naturally  expect  its  people  to  be  com- 
paratively free  from  poverty  and  its  allied  evils.  The 
problems  that  menace  the  older  civilizations  of  the  East, 
overcrowding,  starvation  wages,  and  lack  of  employment, 
are  hardly  felt  there,  and  it  is  not  fair  to  claim  as  the 
outcome  of  one  law  the  results  that  are  due  to  many 
causes.  .  .  . 

"  One  charge  has  repeatedly  been  brought  against  the  law 
in  this  State — that  it  has  checked  the  inflow  of  population. 
1  The  hour  that  ushered  in  prohibition,'  said  the  Democratic 
candidate  for  the  Governorship,  '  closed  our  gates  to  the 
hardy  immigrant,  the  home-seeker,  the  strong  and  sturdy 
class  that  develops  a  country.  ...  It  has  driven  law-abiding 
and  enterprising  citizens  from  the  State.'  Statistics  cer- 
tainly show  a  decrease  in  the  population  within  the  last 
few  years.  There  was  a  great  inflow  of  immigrants  from 
1870  to  1880,  and  from  1880  to  1888  there  was  a  further 
increase  of  the  population  of  from  less  than  a  million  to 
over  a  million  and  a  half.  But  from  1888  to  1890  there 
was  a  decrease  of  about  ninety  thousand.  .  .  .  Since  1890 
the  number  of  inhabitants  has  probably  been  stationary. 


300  AN  OUTLINE  OF  LOGIC 

The  decrease  in  recent  years,  however,  has  been  due,  not 
to  any  State  law,  but  principally  to  the  fact  that  great 
tracts  of  Indian  territory  immediately  below  Kansas  have 
been  opened  up  to  white  men,  and  there  has  been  a  rush 
to  them.  When  the  reduction  is  allowed  for,  Kansas  shows 
a  greater  increase  in  population  from  1880  to  1890  than 
many  of  the  principal  Western  States  in  which  drinking  is 
licensed."  (McKenzie,  Sober  by  Act  of  Parliament,  pp. 
50-52.)  What  is  the  fallacy  that  is  brought  out  in  this 
passage? 

10.  It  was  a  general  belief  at  St.  Kilda  that  the  arrival 
of  a  ship  gave  all  the  inhabitants  colds.  Dr.  John  Campbell 
took  pains  to  ascertain  the  fact  and  to  explain  it  as  the 
effect  of  effluvia  arising  from  human  bodies;  it  was  dis- 
covered, however,  that  the  situation  of  St.  Kilda  renders  a 
northeast  wind  indispensably  necessary  before  a  ship  can 
make  a  landing.     (H.) 

11.  Compare  the  following  two  sets  of  statistics.  Can 
you  suggest  any  way  in  which  the  discrepancy  may  be 
explained  ? 

(a)  "  The  report  of  the  collective  investigation  commit- 
tee of  the  British  Medical  Association,  on  the  subject  of 
1  Temperance  and  Health,'  and  the  results  embodied  in  it, 
are  both  interesting  and  important. 

"A  schedule  of  inquiries  was  forwarded  to  all  members 
of  the  British  Medical  Association,  one  hundred  and  seventy- 
eight  of  whom  responded,  and  gave  hi  the  aggregate  par- 
ticulars regarding  four  thousand  two  hundred  and  thirty- 
four  cases  of  deceased  lives,  aged  twenty-five  and  upward, 
in  which  the  alcoholic  habits  of  the  lives  were  recorded. 
For  the  purposes  of  the  investigation,  the  habits  of  the 
deceased  with  reference  to  alcohol  were  divided  into  five 
classes,  namely:  (a)  total  abstainers;  (b)  habitually  tem- 
perate; (c)  careless  drinkers;  (d)  free  drinkers;  (e)  de- 
cidedly intemperate.  The  ages  of  death  of  those  in  each 
class  were  registered,  together  with  the  causes  of  death; 


EXERCISES  301 

and  the  average  of  death  for  each  class  is  given  in  the 
following  schedule: 

Total  abstainers   51 .22  years 

Habitually  temperate  drinkers.     63.13      " 

Careless  drinkers   59 .  67      " 

Free  drinkers   57.59      " 

Decidedly  intemperate  drinkers.    53.03      " 

(Quoted  in  the  Arena,  Vol.  8,  pp.  209-210.) 

(b)  "As  to  the  relative  healthfulness  of  temperance  or 
drink  the  tables  yearly  made  up  by  the  United  Kingdom 
Temperance  and  General  Provident  Institution  for  Mutual 
Life  Insurance  (established  1840)  afford  conclusive  prac- 
tical evidence.  The  secretary  of  this  institution,  Mr.  Thomas 
Cash,  kindly  furnished  me  with  the  following  condensed 
but  lucid  statement: 

Temperance  Section.  General  Section. 

Expected  Artn&l  Expected        Artnal 

Claims.  Actual.  claims.  Actual. 

1866-70  (five  years) . .  549  411  1008  944 

1871-75  (five  years) . .  723  511  1268  1330 

1876-80  (five  years) . .  933  651  1485  1480 

1881-82  (two  years) . .  439  288  647  585 


Total  (17  years) . . .  2644  1861  4408  4339 

"  It  will  be  seen  from  this  that  the  claims  in  the  tem- 
perance section  are  only  a  little  over  seventy  per  cent,  of 
the  expectancy,  while  in  the  general  section  they  are  but 
slightly  below  expectancy."  (Axel  Gustafson,  The  Founda- 
tion of  Death,  p.  268.) 

12.  "  On  the  eve  of  the  War  of  1812,  Congress  guarded 
the  national  strength  by  enacting  a  highly  protective  tariff. 
By  its  own  terms  this  tariff  must  end  with  the  war.  When 
the  new  tariff  was  to  be  formed,  a  popular  cry  arose  against 
1  war  duties,'  though  the  country  had  prospered  under  them 


302  AN  OUTLINE  OF  LOGIC 

despite  the  exhausting  effect  of  the  struggle  with  Great 
Britain.  But  the  prayer  of  the  people  was  answered,  and 
the  war  duties  were  dropped  from  the  tariff  of  1816.  The 
business  of  the  country  was  speedily  prostrated.  The  people 
were  soon  reduced  to  as  great  distress  as  in  that  melancholy 
period  between  the  close  of  the  Revolutionary  War  and  the 
organization  of  the  National  Government — 1783  to  1789.  .  .  . 

"  Relief  came  at  last  with  the  enactment  of  the  protective 
tariff  of  1824,  to  the  support  of  which  leading  men  of 
both  parties  patriotically  united  for  the  common  good.  That 
act,  supplemented  by  the  act  of  1828,  brought  genuine 
prosperity  to  the  country.  The  credit  of  passing  the  two 
protective  acts  was  not  due  to  one  party  alone.  It  was  the 
work  of  the  great  men  of  both  parties.  .  .  .  "We  have  their 
concurrent  testimony  that  the  seven  years  preceding  the 
enactment  of  the  protective  tariff  of  1824  were  the  most 
discouraging  which  the  young  Republic  in  its  brief  life  had 
encountered,  and  that  the  seven  years  which  followed  its 
enactment  were  beyond  precedent  the  most  prosperous  and 
happy. 

"  Sectional  jealousy  and  partisan  zeal  could  not  endure 
the  great  development  of  manufactures  hi  the  North  and 
East  which  followed  the  apparently  firm  establishment  of 
the  protective  policy.  The  free-trade  leaders  of  the  South 
believed — at  least  they  persuaded  others  to  believe — that 
the  manufacturing  States  were  prospering  at  the  expense 
of  the  planting  States.  .  .  .  Out  of  this  strange  complica- 
tion came,  not  unnaturally,  the  sacrifice  of  the  protective 
tariff  of  1824-8  and  the  substitution  of  the  compromise  tariff 
of  1833,  which  established  an  ad  valorem  duty  of  20  per 
cent,  on  all  imports,  and  reduced  the  excess  over  that  by 
a  10  per  cent,  annual  sliding  scale  for  the  ensuing  ten 
years.  .  .  . 

"  For  a  time  satisfaction  was  felt  with  the  tariff  adjust- 
ment of  1833,  because  it  was  regarded  as  at  least  a  tempo- 
rary reconciliation  between  two  sections  of  the  Union.    Be- 


EXERCISES  303 

fore  the  sliding  scale  was  ruinously  advanced,  there  was 
great  stimulus  to  manufacturing  and  to  trade,  which  finally 
assumed  the  form  of  dangerous  speculation.  The  years 
1834,  1835,  and  1836  were  distinguished  for  all  manner  of 
business  hazard,  and  before  the  fourth  year  opened,  the 
30  per  cent,  reduction  (three  years  of  10  per  cent,  each) 
on  the  scale  of  duties  was  beginning  to  influence  trade 
unfavorably.  The  apprehension  of  evil  soon  became  general, 
the  panic  of  1837  ensued,  and  business  reversals  were 
rapid,  general,  and  devastating.  .  .  .  There  was  no  relief 
to  the  people  until  the  protective  tariff  of  1S42  was  enacted; 
and  then  the  beneficent  experience  of  1824  was  repeated 
on  even  a  more  extensive  scale.  Prosperity,  wide  and 
general,  was  at  once  restored.  But  the  reinstatement  of 
the  Democratic  party  to  power,  two  years  later,  by  the 
election  of  Mr.  Polk  to  the  Presidency,  followed  by  a  per- 
verse violation  of  public  pledges  on  the  part  of  men  in 
important  places  of  administration,  led  to  the  repeal  of 
the  protective  act  and  the  substitution  of  the  [disastrous 
free-trade]  tariff  of  1846.  ...  If  these  disasters  of  1857, 
flowing  from  the  free-trade  tariff,  could  have  been  regarded 
as  exceptional,  if  they  had  been  without  parallel  or  prece- 
dent, they  might  not  have  had  so  deadly  a  significance. 
But  [as  has  been  shown]  the  American  people  had  twice 
before  passed  through  a  similar  experience.  .  .  . 

"  Measuring,  therefore,  from  1812,  when  a  protective 
tariff  was  enacted  to  give  strength  and  stability  to  the  gov- 
ernment in  the  approaching  war  with  Great  Britain,  to 
1861,  when  a  protective  tariff  was  enacted  to  give  strength 
and  stability  to  the  government  in  the  impending  revolt 
of  the  Southern  States,  we  have  fifty  years  of  suggestive 
experience  in  the  history  of  the  Republic.  During  this  long 
period  free-trade  tariffs  were  thrice  followed  by  industrial 
stagnation,  by  financial  embarrassment,  by  distress  among 
all  classes  dependent  for  subsistence  upon  their  own  labor. 
Thrice  were  these  burdens  removed  by  the  enactment  of  a 


304  AN  OUTLINE  OF  LOGIC 

protective  tariff.  Thrice  the  protective  tariff  promptly  led 
to  industrial  activity,  to  financial  ease,  to  prosperity  among 
the  people.  And  this  happy  condition  lasted  in  each  ease, 
with  no  diminution  of  its  beneficent  influence,  until  illegiti- 
mate political  combinations,  having  their  origin  in  personal 
and  sectional  aims,  precipitated  another  era  of  free  trade. 
A  perfectly  impartial  man,  unswerved  by  the  excitement 
which  this  question  engenders  in  popular  discussion,  might 
safely  be  asked  if  the  half-century's  experience,  with  its 
three  trials  of  both  systems,  did  not  establish  the  wisdom 
of  protection  in  the  United  States.  If  the  inductive  method 
of  reasoning  may  be  trusted,  we  certainly  have  a  logical 
basis  of  conclusion  in  the  facts  here  detailed. 

"  As  an  offset  to  the  charge  that  free-trade  tariffs  have 
always  ended  in  panics  and  long  periods  of  financial  dis- 
tress, the  advocates  of  free  trade  point  to  the  fact  that  a 
financial  panic  of  great  severity  fell  upon  the  country  in 
1873,  when  the  protective  tariff  of  1861  was  in  full  force, 
and  that,  therefore,  panic  and  distress  follow  periods  of 
protection  as  well  as  periods  of  free  trade.  It  is  true  that 
a  financial  panic  occurred  in  1873,  and  its  existence  would 
blunt  the  force  of  my  argument  if  there  were  not  an  im- 
peratively truthful  way  of  accounting  for  it  as  a  distinct 
result  from  entirely  distinct  causes.  The  panic  of  1873 
was  widely  different  in  its  true  origin  from  those  which  I 
have  been  exposing.  The  Civil  War,  which  closed  in  1865, 
had  sacrificed  on  both  sides  a  vast  amount  of  property  .  .  . 
The  situation  was  without  parallel.  The  speculative  mania 
which  always  accompanies  war  had  swollen  private  obliga- 
tions to  a  perilous  extent.  .  .  .  And,  strongest  of  all  points, 
the  financial  distress  was  relieved  and  prosperity  restored 
under  protection,  whereas  the  ruinous  effects  of  panics  under 
free  trade  have  never  been  removed  except  by  resort  to 
protection.  .  .  .  Viewing  the  country  from  1861  to  1889 — 
full  twenty-eight  years — the  longest  undisturbed  period  in 
which  either  protection  or  free  trade  has  been  tried  in  this 


EXERCISES  305 

country,  I  ask  if  a  parallel  can  be  found  to  the  material 
advancement  of  the  United  States."  (J.  G.  Blaine,  North 
American  Review,  Vol.  150,  pp.  33-9.)  (One  sentence  has 
been  transposed.) 

13.  "  The  drink  question  makes  an  easy  and  natural  ful- 
crum from  which  to  work  a  number  of  levers  of  the  pseudo- 
philanthropic  order.  The  wrong  and  pain  which  stand  in 
visible  connection  with  the  excessive  use  of  intoxicants  are 
only  too  obvious.  Any  judge,  any  magistrate,  any  police- 
man, any  district  visitor  can  speak  to  them.  And  when  one 
begins,  all  the  rest  follow  like  sheep.  Some  Recorder  of 
Cindertown,  or  some  Deputy-Assistant-Judge,  remarks  that 
half  the  crimes  of  violence  that  come  under  his  notice  in 
his  judicial  capacity  are  traceable  to  drink — this  profound 
observation  is  reported  hi  a  hundred  newspapers — and 
within  a  twelvemonth  all  the  judges  in  the  kingdom  are 
echoing  the  Recorder  of  Cindertown.  The  learned  gentle- 
man gets  his  social  science  cheap.  Anybody  can  see  that 
a  bad  man  of  a  certain  quality  must  be  made  worse  by 
half-a-pint  of  bad  gin,  or  even  good  gin;  but  it  is  not 
everybody  who  will  pause  to  reflect  that  the  learned  gentle- 
man might  just  as  truly  remark  that  in  half  the  cases  of 
crimes  of  violence  that  came  under  his  notice  the  offenders 
wore  dirty  linen,  and  never  brushed  their  teeth;  and  that 
in  the  other  half  the  culprits  were  subject  to  chronic  dys- 
pepsia, and  never  read  Milton's  '  Comus.'  Then  the  remedy 
for  all  this  misery  seems  easy.  The  murderer  or  the  wife- 
beater  did  this  under  the  influence  of  gin — that  is  the  first 
step.  He  bought  his  gin  at  the  '  Pig  and  Whistle ' — that 
is  the  second  step.  The  third  step  is  plain  to  the  meanest 
capacity — shut  up  the  '  Pig  and  Whistle,'  and  there  is  an 
end  of  murder.  Add  to  this  that  the  rates  will  be  greatly 
reduced,  being  careful  to  say  nothing  of  the  expenditure 
that  will  have  to  be  incurred  in  carrying  out  your  new  law, 
and  you  have  full-blown  social  science  for  Mrs.  Nickleby 
in  excelsis.     And  you  supply  a  fine  fulcrum  in  public  dis- 


306  AN  OUTLINE  OF  LOGIC 

cussiou  for  other  philanthropic  crotcheteers,  as  indifferent 
as  you  are  to  the  rights  of  the  blameless  classes  of  the 
community,  and  bent,  as  you  are,  upon  sacrificing  these  to 
the  wretched,  all-but-worthless  minority  whom  the  turn  of 
a  feather's  weight  pushes  over  into  cruel  and  filthy  violence. 
Now,  I  protest  against  this."  {Contemporary  Review,  Vol. 
30,  pp.  457-8.) 

14.  "  Five  years  ago  a  first-class  pair  of  nickel-plated 
steel  skates,  with  the  necessary  clamps  to  fasten  them  to 
the  boot  or  shoe,  cost  $15.  To-day  precisely  the  same  article, 
and  with  an  equal  finish  and  completeness,  can  be  obtained 
for  $4.  Three  years  ago  a  second  grade  of  nickel-plated 
steel  skates  cost  $4.  The  same  article  can  be  produced  to- 
day for  $1.50.  The  decline  of  seventy  per  cent,  in  five  years, 
and  of  sixty  per  cent,  in  three  years,  shows  just  how  pro- 
tection cheapens  prices."  (Milwaukee  Evening  Wisconsin, 
quoted  by  Hyslop,  Elements  of  Logic.) 


CHAPTER  XI 

Determine  the  nature  of  the  following  arguments  and 
judge  of  their  validity: 

1.  "  We  should  think  it  a  sin  and  a  shame  if  a  great 
steamer,  dashing  across  the  ocean,  were  not  brought  to  a 
stop  at  a  signal  of  distress  from  the  mere  smack.  .  .  . 
And  yet  a  miner  is  entombed  alive,  a  painter  falls  from  a 
scaffold,  a  brakeman  is  crushed  in  coupling  cars,  a  merchant 
fails,  falls  ill,  and  dies,  and  organized  society  leaves  widow 
and  child  to  bitter  want  or  degrading  alms."  (Henry 
George,  Protection  and  Free  Trade,  from  Creighton,  p.  377.) 

2.  "  The  missionary  [Dr.  Livingstone]  was  trying  to  dis- 
suade the  savage  from  his  fetichistic  ways  of  invoking  rain. 
'  You  see/  said  he,  '  that  after  all  your  operations,  some- 
times it  rains  and  sometimes  it  does  not,  exactly  as  when 
you  have  not  operated  at  all.'    '  But,'  replied  the  sorcerer, 


EXERCISES  307 

'  it  is  just  the  same  with  you  doctors ;  you  give  your 
remedies,  and  sometimes  the  patient  gets  well  and  some- 
times he  dies,  just  as  when  you  do  nothing  at  all.'  To  that 
the  pious  missionary  replied :  '  The  doctor  does  his  duty, 
after  which  God  performs  the  cure  if  it  pleases  Him.' 
'  Well,'  rejoined  the  savage,  '  it  is  just  so  with  me.  I  do 
what  is  necessary  to  procure  ram,  after  which  God  sends  it 
or  withholds  it  according  to  His  pleasure.' "  (James,  Psy- 
chology, Vol.  II.,  p.  363.) 

3.  "  If  the  Prohibitionists  want  to  prohibit  everything 
that  has  evil  in  it,  let  them  be  consistent  and  stop  not  at 
alcohol,  but  go  a  little  further  and  include  the  human 
tongue,  of  which  the  Bible  says,  '  The  tongue  can  no  man 
tame.  It  is  an  unruly  evil,  full  of  deadly  poison;  therewith 
we  bless  God,  even  the  Father,  and  therewith  curse  we  men 
made  after  the  similitude  of  God.'  (James  iii:  8,  9.)  Here 
is  evil  and  good  combined  in  the  same  thing,  just  owing  to 
whether  it  is  properly  or  improperly  used,  and  the  same 
is  equally  true  of  alcohol;  although  the  Prohibitionists  seem 
unwilling  to  admit  there  is  anything  but  evil  in  it."  ( Arena, 
Vol.  8,  p.  205.) 

4.  "What  reply  can  be  made  to  the  following'? — 'You 
say  that  the  prisoner  is  probably  guilty.  I  grant  it.  But 
this  only  means  that  the  prisoners  in  most  cases  of  this 
sort  are  guilty.  It  does  not  mean  that  this  particular 
prisoner  has  even  a  touch  of  guilt.  Your  very  use  of  the 
word  '  probable '  is  a  confession  that  for  all  you  know  he 
may  be  absolutely  innocent.  How  then  can  you  ask  the 
jury  to  condemn  him  to  an  awful  fate?"     (A.) 

5.  "  That  they  [the  colonists]  inherit  the  rights  of  their 
ancestors;  is  allowed;  but  they  can  inherit  no  more.  .  .  . 
The  colonists  are  the  descendants  of  men,  who  either  had 
no  vote  in  elections,  or  who  voluntarily  resigned  them  for 
something,  in  their  opinion,  of  more  estimation;  they  have 
therefore  exactly  what  their  ancestors  left  them,  not  a 
vote  in   making  laws,   or  in   constituting  legislators,   but 


308  AN  OUTLINE  OF  LOGIC 

the  happiness  of  being  protected  by  law,  and  the  duty  of 
obeying  it. 

"  What  their  ancestors  did  not  carry  with  them,  neither 
they  nor  their  descendants  have  since  acquired.  They  have 
not,  by  abandoning  their  part  in  one  legislature,  obtained 
the  power  of  constituting  another,  exclusive  and  independ- 
ent, any  more  than  the  multitudes,  who  are  now  debarred 
from  voting,  have  a  right  to  erect  a  separate  parliament 
for  themselves."     (Johnson,  Taxation  no  Tyranny.) 

6.  "  The  existence  of  hell  may  even  be,  in  one  sense,  an 
evidence  of  God's  mercy  as  well  as  his  justice.  It  may  be 
the  best  thing  that  can  be  done  for  natures  which  have 
confirmed  themselves  in  sin.  Suppose  it  had  been  proposed 
to  Benedict  Arnold,  after  his  apostasy,  to  return  to  the 
colonies — ask  the  pardon  of  Washington — confess  his  wicked 
duplicity  and  treachery,  and  on  these  conditions  be  restored 
to  citizenship.  He  would  have  known  that  such  a  course 
would  promote  his  happiness,  yet  without  a  change  of  prin- 
ciple, he  would  have  rejected  it  with  contempt.  Suppose 
further,  that  when  the  war  was  finished,  and  Washington 
had  put  down  all  power  adverse  to  the  happiness  of  the 
colonies,  Arnold  was  found  among  the  prisoners,  having 
contended  as  long  as  he  could  against  the  government.  His 
situation  was  now  such,  that  any  confession  that  he  might 
make,  or  any  pardon  for  which  he  might  ask,  could  pro- 
ceed from  no  other  than  selfish  motives.  When  men  fall 
into  the  hands  of  the  living  God,  or  into  the  hands  of  the 
executor  of  the  law,  repentance  and  love  to  the  lawgiver 
are  then  impossible,  because  the  motive  determines  the  char- 
acter of  the  act,  and  right  motives  in  acting  would  then 
be  impossible,  because  they  would  be  necessarily  selfish. 

"  Now,  then,  seeing  repentance  and  love  for  the  governor 
under  such  circumstances  would  be  impossible,  suppose  the 
alternative  had  been  proposed  to  Arnold  either  to  spend  his 
life  in  the  presence  of  Washington,  and  in  the  society  of 
those  who  knew  him  to  be  a  traitor  at  heart;  or  to  be 


EXERCISES  309 

banished  to  an  island  which  contained  only  rebels  and 
criminals  like  himself,  he  would  undoubtedly  have  chosen 
the  latter  immediately.  Because,  although  the  island  would 
be  a  hell  on  account  of  the  remorse  of  guilty  consciences 
and  the  rage  of  evil  passions  that  would  exist  and  increase 
there,  yet  his  nature  had  become  so  corrupted,  that  to  live 
under  the  eye  of  the  magnanimous  Washington,  and  amid 
those  who  abhorred  bad  principles,  would  have  been  to  his 
soul  severer  punishment  than  to  live  among  the  guilty  and 
condemned  in  the  island. 

"  Now,  suppose  Washington  (knowing  that  his  apostasy 
had  so  corrupted  his  nature  that  he  would  be  less  miserable 
to  be  banished  from  his  presence  than  to  continue  in  the 
society  that  made  patriots  happy),  in  view  of  his  past  life, 
and  in  view  of  the  character  he  then  possessed,  had  banished 
him  forever  from  his  presence,  such  banishment  would  have 
been  not  only  an  exhibition  of  justice  but  of  mercy,  and 
it  would  have  been  the  best  thing  that  could  have  been 
done  for  the  man  in  view  of  his  character  and  circumstances. 
So  with  God.  Banishment  to  hell  is  the  best  thing  that  can 
be  done  for  those  who  die  in  rebellion;  therefore  God  has, 
in  justice  and  mercy,  provided  a  hell  for  fallen  angels  and 
impenitent  sinners,  who  die  unpardoned  and  unreconciled  to 
God."     (Walker,  Philosophy  of  Scepticism,  pp.  151-3.) 

7.  Old  age  is  wiser  than  youth;  therefore  it  is  only 
reasonable  that  we  should  be  guided  by  the  decisions  of 
our  ancestors. 

8.  Two  students  who  have  never  been  suspected  of  dis- 
honesty sit  near  each  other  in  an  examination  and  each 
of  them  writes  these  very  words:  "Henry  George  was  the 
great  orator  of  the  Revolution;  it  was  he  who  said  in 
Faneuil  Hall,  '  Give  me  liberty  or  give  me  life.' "  What 
inference  can  be  drawn  from  this  coincidence  ?  How  much 
should  the  inference  be  affected  by  the  protests  of  the 
students  that  they  were  perfectly  honest,  or  by  their  ex- 
planation that  they  had  studied  together?     (A.) 


310  AN  OUTLINE  OF  LOGIC 

9.  "Manufacturing  countries  are  always  rich  countries; 
countries  that  produce  raw  material  are  always  poor. 
Therefore,  if  we  would  be  rich,  we  must  have  manufactures, 
and  in  order  to  get  them,  we  must  encourage  them.  .  .  . 
But  I  could  make  as  good  an  argument  to  the  little  town 
of  Jamaica.  ...  In  support  of  a  subsidy  to  a  theater,  I 
could  say  to  them:  all  cities  have  theaters  and  the  more 
theaters  it  has  the  larger  the  city.  Look  at  New  York !  .  .  . 
Philadelphia  ranks  next  to  New  York  in  the  number  and 
size  of  its  theaters,  and  therefore  comes  next  to  New  York 
in  wealth  and  population.  ...  I  might  then  drop  into 
statistics  .  .  .  and  point  to  the  fact  that  when  theatrical 
representations  began  in  this  country,  its  population  did  not 
amount  to  a  million,  that  it  was  totally  destitute  of  railroads, 
and  without  a  single  mile  of  telegraph  wire.  Such  has 
been  our  progress  since  theaters  were  introduced  that 
the  census  of  1880  showed  we  had  50,155,783  people, 
90,907  miles  of  railroad,  and  291,212ft  miles  of 
telegraph  wires."  (Henry  George,  quoted  by  Creighton, 
p.  377.) 

10.  "  The  canvas  Raphael  painted  has  endured  for  three 
centuries.  But  has  God  ordained  that  the  canvas  shall  be 
preserved  while  the  artist  has  fallen  into  dust  ?  Is  '  In 
Memoriam'  more  than  Tennyson?  Is  St.  Paul's  Cathedral 
more  than  Sir  Christopher  Wren,  its  architect?  Is  the 
leaf  to  live,  while  the  tree  dies?  Reason  and  conscience 
whisper,  it  cannot  be.  If  thoughts  live,  the  thinker  can- 
not die.  To  suppose  that  death  ends  all  is  intellectually  as 
absurd  as  it  is  morally  monstrous."  (N.  D.  Hillis,  Fore- 
tokens of  Immortality.) 

11.  "  The  soul  is  indivisible,  incorporeal,  unextended,  and 
is  consequently  incorruptible.  Nothing  can  be  plainer  than 
that  the  motions,  changes,  decays,  and  dissolutions  which  we 
hourly  see  befall  natural  bodies  .  .  .  cannot  possibly 
affect  an  active,  simple,  uncompounded  substance;  such  a 
being  therefore  is  indissoluble  by  the  force  of  nature;  that 


EXERCISES  311 

is    to    say,    '  the    soul    of    man    is    naturally    immortal.' " 
(Berkeley,  The  Principles  of  Human  Knowledge,  §  141.) 

CHAPTER  XII 

Examine  the  following  arguments: 

1.  Should  a  church  accept  a  saloon-keeper's  gift  (assum- 
ing that  the  church  is  justified  in  condemning  the  latter's 
business)  ?  Consider  the  following  discussions  of  the 
question : 

(a)  "If  we  are  to  rule  out  all  contributors  to  church 
purposes,  who  are  engaged  in  businesses  that  are  not  to  some 
folks'  liking,  we  will  very  soon  find  that  we  are  making  a 
mistake.  '  The  whole  need  no  physician.'  We  should  take 
such  people  into  the  congregation  and  try  to  make  good 
Christians  of  them,  instead  of  beginning  by  shutting  the 
door  in  their  faces  and  flinging  their  gifts  after  them." 

(b)  "  I  am  not  a  believer  in  saloons,  but  in  regard  to 
receiving  money  from  a  saloon,  I  think  it  is  just  as  good  as 
another  store  or  a  private  house.  The  saloon  had  to  sell 
in  exchange  for  the  money  as  another  store  would  have 
to  do." 

(c)  "  Saloon  money  is  the  price  of  broken  hearts.  Now 
for  the  Christian  church  to  take  the  price  of  blood  and 
offer  it  to  God  in  sacrifice  to  carry  forward  his  work  in 
saving  men  would  simply  be  an  insult." 

(d)  "  How  can  a  church  innocently  accept  and  use  for 
the  furtherance  of  the  world's  evangelization,  money  passed 
over  the  bar  in  the  grog-shop1?  Impossible,  for  besides  the 
fact  that  it  would  be  the  receiver  of  stolen  goods,  there  is  the 
added  guilt  of  the  knowledge  that  it  was  stolen.  The  voice 
of  victimized  maidenhood,  of  abandoned  wifehood,  robbed 
womanhood,  and  impoverished  childhood  cry  out  in  anguish 
against  such  an  appalling  injustice.  The  anguish  of  lost 
character  and  dehumanized  manhood  sound  above  the  strife 
of  nations  against  this  dreadful  sin.    The  ring  of  the  thirty 


312  AN  OUTLINE  OF  LOGIC 

pieces  of  silver  as  Judas  flung  them  down  on  the  marble 
floor  was  music  to  his  ear,  as  compared  with  the  unutterable 
and  unbearable  torture  of  the  voice  of  his  remorseful  con- 
science for  having  received  the  price  of  blood.  If  we  have 
but  a  spark  of  conscience  within  us,  can  we  fail  to  see 
at  once  in  this  not  only  blood  money,  but  the  price  of  a 
soul?  In  the  name  of  the  world's  blessed  Redeemer — quick 
— '  Get  thee  behind  me,  Satan.'  " 

(e)  "Take  it!  If  this  money  had  a  soul,  it  would  cry 
out  from  its  uttermost  depths :  '  Give  me  the  opportunity ! 
I  have  been  forced  into  channels  of  darkness  and  evil! 
And  now  a  ray  of  light  and  blessing  beams  on  me.  Oh, 
keep  me  not  back.'  If  we  refuse  the  money  because  of  evil 
channels  through  which  it  comes,  shall  we  not  refuse  other 
money  for  the  same  cause?  And  is  not  all  money  in  this 
sense  more  or  less  contaminated  ?  Yes.  Take  it ;  delay  not, 
lest  it  be  forced  back  to  promote  the  greatest  source  of 
crime  and  brutality.  Take  it,  that  it  may  expand  the  church, 
its  soul-saving,  its  charities,  its  blessed  missions,  and  glorify 
God  who  gave  it."  (From  the  Christian  Herald,  August  23, 
1899.) 

2.  What  is  the  correct  attitude  as  regards  "  tainted 
money  "  ?     Consider  the  following  arguments : 

(a)  "  There  is  no  such  thing  as  tainted  money,"  declared 
a  college  president  recently.  "  Human  conduct  in  acquiring 
money  does  not  attach  to  nor  mix  in  the  coin,  nor  lessen 
nor  weaken  the  promise  to  pay  upon  the  bank  note.  There 
is  no  such  thing  as  '  tainted  money.'  Good  moral  money — 
that  is,  coin  of  full  weight,  and  live  promises  to  pay — 
good  coin  is  good  anywhere,  in  any  man's  hand.  Truth 
takes  no  passing  shadow  to  itself,  and  money  cannot  be 
impregnated  by  the  deeds  of  passing  users.  Having  this 
view  of  good  money,  I  will  accept  it  from  any  man  who 
owns  it." 

(b)  "  It  seems  to  me  that  instead  of  indignantly  refusing 
large  gifts  from  any  one  disposed  to  give  for  charitable 


EXERCISES  313 

purposes,  on  the  ground  that  the  money  offered  by  them  is 
or  was  'tainted/  i.e.,  earned  in  a  manner  not  in  accord 
with  the  popular  idea  of  fair  dealing,  or  secured  by  detri- 
mental business  practices,  that  it  should  be  the  duty  of  all 
Christians  and  charitably  inclined  people  and  good  intenders 
to  take  all  money  offered  for  any  good  purpose.  Why? 
Because  every  dollar  taken  from  a  man  or  firm  engaged 
in  evil  or  corrupt  business,  or  who  is  a  party  to  corrupt 
or  evil  methods  in  the  conducting  of  a  legitimate  business, 
is  a  dollar's  worth  of  power  converted  from  evil  to  a  good 
purpose." 

3.  " '  Speakin'  o'  money,'  said  the  night-watchman 
thoughtfully,  as  he  selected  an  empty  soap-box  on  the  wharf 
for  a  seat,  '  the  whole  world  would  be  different  if  we  all  'ad 
more  of  it.  It  would  be  a  brighter  and  a  'appier  place  for 
everybody.' "     (W.  W.  Jacobs,  Light  Freights,  p.  1.) 

4.  "  None  of  us  can  weigh  or  judge  desert.  No  man 
can  say,  even  of  the  seemingly  vilest  criminal,  whether  he 
is  guilty  or  unfortunate.  Take  the  foulest  murderer  you 
know  of: — can  you  inform  us  whether  that  wretched  crea- 
ture has  ever  been  so  instructed  in  morality  as  to  know  what 
he  has  done? — can  you  tell  us  whether  he  has  mind  enough 
to  be  responsible  to  justice? — can  you  satisfy  us  as  to  his 
hereditary  dispositions — as  to  his  sanity — as  to  the  impulse 
which  led  him  to  commit  his  crime — as  to  his  education, 
parentage,  early  habits — as  to  the  strength  of  the  tempta- 
tion which  conquered  him — as  to  his  innate  power  of  re- 
sistance? Can  you  even  say  whether  his  brain  is  healthy 
or  diseased?  No!  you  cannot  speak  as  to  one  of  these 
essential  points;  and  yet  you  pretend  to  judge  him  (as 
you  pray  that  God  will  not  judge  you)  '  according  to 
desert.'"  (Eclectic  Review,  March,  1850,  p.  225.)  What 
answer  can  be  made  to  this? 

5.  "  Clearly,  '  without  free  agency  there  can  be  no  moral- 
ity,' and  '  without  temptation  no  virtue,'  and  it  is  not  con- 
sistent with  the  laws  of  Providence  that  because  some  abuse 


314  AN  OUTLINE  OF  LOGIC 

an  article  which  is  good  in  itself  [liquor],  the  vast  multitude 
should,  in  consequence,  be  denied  its  use.  This  would  be 
punishing  the  innocent  many  for  the  sins  of  the  guilty 
few."     (Arena,  Vol.  8,  p.  206.) 

6.  "  Covetousness  .  .  .  being  the  root  of  all  evil,  should 
be  early  and  carefully  weeded  out,  and  the  contrary  quality 
of  a  readiness  to  impart  to  others  implanted.  This  should 
be  encouraged  by  great  commendation  and  credit,  and  con- 
stantly taking  care  that  [the  child]  loses  nothing  by  his 
liberality.  Let  all  the  instances  he  gives  of  such  freeness 
be  always  repaid,  and  with  interest;  and  let  him  sensibly 
perceive  that  the  kindness  he  shows  to  others  is  no  ill 
husbandry  for  himself,  but  that  it  brings  a  return  of  kind- 
ness both  from  those  that  receive  it  and  those  who  look 
on."  (Locke,  Some  Thoughts  Concerning  Education,  §110; 
quoted  by  Welton,  p.  273.) 

7.  "But  (say  you)  it  doth  but  make  men  hypocrites  to 
compel  men  to  conform  the  outward  man  [in  matters  of 
worship]  for  fear  of  punishment.  If  it  did  so,  yet  better 
to  be  hypocrites  than  profane  persons.  Hypocrites  give 
God  part  of  his  due,  the  outward  man,  but  the  profane  per- 
son giveth   God  neither  outward  nor  inward  man.   .   .   . 

"  You  know  not,  if  you  think  we  came  into  this  wilderness 
to  practice  those  courses  [viz.,  religious  oppression]  here 
which  we  fled  from  in  England.  We  believe  there  is  a  vast 
difference  between  men's  inventions  and  God's  institutions; 
we  fled  from  men's  inventions,  to  which  we  else  should 
have  been  compelled;  we  compel  none  to  men's  in- 
ventions." (John  Cotton,  Hutchinson  Papers,  Vol.  II., 
p.  132.) 

8.  "  Parson  Lingon  argues  in  favor  of  cock-fighting,  not 
only  that  under  it  'England  had  been  prosperous  and 
glorious,'  but  that  'the  practice  sharpened  the  faculties  of 
men,  gratified  the  instincts  of  the  fowl,  and  earned  out 
the  designs  of  heaven  in  its  admirable  device  of  spurs 
(Sidgwick,  Fallacies,  p.  21G,  note.)     Discuss  this. 


t » 


EXERCISES  315 

9.  "  The  Supreme  Court  of  Colorado,  in  the  decision  by 
which  it  annulled  the  miners'  eight  hour  law,  asserts  the 
principle  that  while  the  sanitary  power  extends  to  the 
protection  of  the  health  of  the  community  at  large,  and 
even  of  the  health  of  portions  and  classes  of  the  community, 
yet  it  may  not  be  exercised  so  as  to  protect  these  classes 
from  their  own  acts.  '  The  reason  for  the  existence  of 
the  power  rests  upon  the  theory  that  one  must  so  use  its 
own  as  not  to  hi  jure  others,  and  so  as  not  to  interfere 
with  or  injure  the  public  health,  safety,  morals,  or  the 
general  welfare.  How  can  one  be  said  injuriously  to  affect 
others,  or  interfere  with  these  great  objects,  by  doing  an 
act  which  confessedly  visits  its  consequences  on  himself 
alone?  And  how  can  an  alleged  law  that  purports  to 
be  the  result  of  an  exercise  of  the  police  power  be  such  in 
reality,  when  it  has  for  its  only  object,  not  the  protection 
of  others  or  the  public  health,  safety,  morals,  or  general 
welfare,  but  the  welfare  of  him  whose  act  is  prohibited, 
when,  if  committed,  it  will  injure  him  who  commits  it, 
and  him  alone?'"     (Freund,  Police  Power,  §155.) 

10.  Read  carefully  the  following  extract  from  an  article 
on  "  The  Certainty  of  Endless  Punishment,"  show  to  what 
type  of  argument  it  belongs,  write  a  summary  or  outline, 
and  suggest  criticism: 

"  The  chief  objections  to  the  doctrine  of  endless  punish- 
ment are  not  Biblical  but  speculative.  ...  So  long  as  the 
controversy  is  carried  on  by  an  appeal  to  the  Bible,  the 
defender  of  endless  retribution  has  comparatively  an  easy 
task.  But  when  the  appeal  is  made  to  human  feeling  and 
sentiment,  or  to  ratiocination,  the  demonstration  requires 
more  effort.  And  yet  the  doctrine  is  not  only  Biblical  but 
rational.  It  is  defensible  on  the  basis  of  sound  ethics  and 
pure  reason.  Nothing  is  requisite  for  its  maintenance  but 
the  admission  of  three  cardinal  truths  of  theism,  namely, 
that  there  is  a  just  God;  that  man  has  a  free  will;  and 
that  shi  is  voluntary  action.    If  these  are  denied,  there  can 


316  AN  OUTLINE  OF  LOGIC 

be  no  defense  of  endless  punishment — or  of  any  other 
doctrine,  except  atheism  and  its  corollaries.  .  .  . 

"  Punishment  is  neither  chastisement  nor  calamity.  Men 
suffer  calamity,  says  Christ,  not  because  they  or  their 
parents  have  sinned,  'but  that  the  Works  of  God  should 
be  made  manifest  in  them.'  Chastisement  is  inflicted  in 
order  to  develop  a  good  but  imperfect  character  already 
formed.  '  The  Lord  loveth  whom  he  chasteneth,'  and  '  what 
son  is  he  whom  the  earthly  father  chasteneth  not? '  Punish- 
ment, on  the  other  hand,  is  retribution,  and  is  not  intended 
to  do  the  work  of  either  calamity  or  chastisement,  but  a 
work  of  its  own.  And  this  work  is  to  vindicate  law,  to 
satisfy  justice.  Punishment,  therefore,  is  wholly  retro- 
spective in  its  primary  aim.  It  looks  back  at  what  has 
been  done  in  the  past.  Its  first  and  great  object  is  requital. 
A  man  is  hung  for  murder,  principally  and  before  all  other 
reasons  because  he  has  transgressed  the  law  forbidding 
murder.  He  is  not  hung  from  a  prospective  aim,  such  as 
his  own  moral  improvement,  or  for  the  purpose  of  deterring 
others  from  committing  murder.  The  remark  of  the  Eng- 
lish judge  to  the  horse  thief,  in  the  days  when  such  theft 
was  capitally  punished,  '  You  are  not  hung  because  you 
have  stolen  a  horse,  but  that  horses  may  not  be  stolen,' 
has  never  been  regarded  as  eminently  judicial.  .  .  . 

"  If  the  good  of  the  public  is  the  true  reason  and  object 
of  punishment,  the  amount  of  it  may  be  fixed  by  the 
end  in  view.  The  criminal  may  be  made  to  suffer  more 
than  his  crime  deserves,  if  the  public  welfare,  in  suppressing 
this  particular  kind  of  crime,  requires  it.  His  personal 
desert  and  responsibility  not  being  the  one  sufficient  reason 
for  his  suffering,  he  may  be  made  to  suffer  as  much  as 
the  public  safety  requires.  It  was  this  theory  of  penalty 
that  led  to  the  multiplication  of  capital  offenses.  The  pre- 
vention of  forgery,  it  was  once  claimed  in  England,  re- 
quired that  the  forger  should  forfeit  his  life,  and  upon 
the  principle  that  punishment  is  for  the  public  protection, 


EXERCISES  317 

and  not  for  strict  and  exact  justice,  an  offense  against 
property  was  expiated  by  human  life.  .  .  . 

"  This  theory  breaks  down  from  whatever  point  it  be 
looked  at.  Suppose  that  there  were  but  one  person  in  the 
universe.  If  he  should  transgress  the  law  of  God,  then, 
upon  the  principle  of  expediency  as  the  ground  of  penalty, 
this  solitary  subject  of  moral  government  could  not  be 
punished — that  is,  visited  with  a  suffering  that  is  purely 
retributive,  and  not  exemplary  or  corrective.  His  act  has 
not  injured  the  public,  for  there  is  no  public.  There  is 
no  need  of  his  suffering  as  an  example  to  deter  others,  for 
there  are  no  others.  But  upon  the  principle  of  justice, 
in  distinction  from  expediency,  this  solitary  subject  of  moral 
government  could  be  punished.  .  .  . 

"  Supposing  it,  now,  to  be  conceded,  that  future  punish- 
ment is  retributive  in  its  essential  nature,  it  follows  that 
it  must  be  endless  from  the  nature  of  the  case.  For,  suffer- 
ing must  continue  as  long  as  the  reason  for  it  continues. 
In  this  respect,  it  is  like  law,  which  lasts  as  long  as  its 
reason  lasts :  ratione  cessante,  cessat  ipsa  lex.  Suffering 
that  is  educational  and  corrective  may  come  to  an  end, 
because  moral  infirmity  and  not  guilt  is  the  reason  for  its 
infliction;  and  moral  infirmity  may  cease  to  exist.  But 
suffering  that  is  penal  can  never  come  to  an  end,  because 
guilt  once  incurred  never  ceases  to  be.  The  lapse  of  time 
does  not  convert  guilt  into  innocence,  as  it  converts  moral 
infirmity  into  moral  strength;  and  therefore  no  time  can 
ever  arrive  when  the  guilt  of  the  criminal  will  cease  to 
deserve  and  demand  its  retribution.  The  reason  for  retribu- 
tion to-day  is  a  reason  forever.  Hence,  when  God  disciplines 
and  educates  his  children,  he  causes  only  a  temporary  suffer- 
ing. In  this  case,  'He  will  not  keep  his  anger  forever.' 
But  when,  as  the  Supreme  Judge,  he  punishes  rebellious 
and  guilty  subjects  of  his  government,  he  causes  an  endless 
suffering.  In  this  case,  '  their  worm  dieth  not,  and  the 
fire  is  not  quenched.'  .  .  . 


313  AN  OUTLINE  OF  LOGIC 

"  The  endlessness  of  future  punishment,  then,  is  implied 
in  the  endlessness  of  guilt  and  condemnation.  When  a 
crime  is  condemned,  it  is  absurd  to  ask,  '  How  long  is  it 
condemned?'  The  verdict  'Guilty  for  ten  days'  was  Hi- 
bernian. Damnation  means  absolute  and  everlasting  dam- 
nation. All  suffering  in  the  next  life,  therefore,  of  which 
the  sufficient  and  justifying  reason  is  guilt,  must  continue 
as  long  as  the  reason  continues;  and  the  reason  is  ever- 
lasting. .  .  . 

"  It  may  be  objected  that,  though  the  guilt  and  damnation 
of  a  crime  be  endless,  it  does  not  follow  that  the  suffering 
inflicted  on  account  of  it  must  be  endless  also,  even  though 
it  be  retributive  and  not  reformatory  in  its  intent.  A 
human  judge  pronounces  a  theft  to  be  endlessly  a  theft,  and 
a  thief  to  be  endlessly  a  thief,  but  he  does  not  sentence  the 
thief  to  an  endless  suffering.  But  this  objection  overlooks 
the  fact  that  human  punishment  is  only  approximate  and 
imperfect,  not  absolute  and  perfect  like  the  divine.  It  is 
not  adjusted  exactly  and  precisely  to  the  whole  guilt  of 
the  offense,  but  is  more  or  less  modified,  first,  by  not  con- 
sidering its  relation  to  God's  honor  and  majesty;  secondly, 
by  human  ignorance  of  the  inward  motives;  and  thirdly, 
by  social  expediency.  .  .  .  Man,  while  not  overlooking  the 
guilt  in  the  case,  has  some  reference  to  the  reformation 
of  the  offender,  and  still  more  to  the  protection  of  society. 
Civil  expediency  and  social  utility  modify  exact  and  strict 
retribution.  .  .  . 

"  The  argument  thus  far  goes  to  prove  that  retribution 
in  distinction  from  correction,  or  punishment  in  distinction 
from  chastisement,  is  endless  from  the  nature  of  the  case. 
We  pass,  now,  to  prove  that  it  is  also  rational  and  right. 

"  Endless  punishment  is  rational,  in  the  first  place,  be- 
cause it  is  supported  by  the  human  conscience.  The  sinner's 
own  conscience  will  '  bear  witness '  and  approve  of  the  con- 
demning sentence.  .  .  .  That  conscience  supports  endless 
retribution,  is  also  evinced  by  the  universality  and  steadiness 


EXERCISES  319 

of  the  dread  of  it.  Mankind  believe  in  hell,  as  they  believe 
in  Divine  Existence,  by  reason  of  their  moral  sense.  .  .  . 

"  In  the  second  place,  endless  punishment  is  rational,  be- 
cause of  the  endlessness  of  sin.  .  .  .  There  are  degrees  in 
future  suffering,  because  it  is  infinite  in  duration  only.  In 
intensity  it  is  finite.  Consequently,  the  lost  do  not  all 
suffer  precisely  alike,  though  all  suffer  the  same  length  of 
time.  .  . .  Sin  is  stubborn  and  obstinate  in  its  nature,  because 
it  is  enmity  and  rebellion.  Hence,  wicked  will  intensifies 
itself  perpetually.  Pride,  left  to  itself,  increases  and  never 
diminishes.  Enmity  and  hatred  become  more  and  more 
satanic.  ...  A  man  is  not  forced  to  sin,  but  if  he  does,  he 
cannot  of  himself  get  back  where  he  was  before  sinning. 
He  cannot  get  back  to  innocency,  nor  can  he  get  back  to 
holiness  of  heart.  The  effect  of  vicious  habit  hi  diminishing 
a  man's  ability  to  resist  temptation  is  proverbial.  .  .  . 

"  In  the  third  place,  endless  punishment  is  rational,  be- 
cause sin  is  an  infinite  evil;  infinite  not  because  committed 
by  an  infinite  being,  but  against  one.  We  reason  invariably 
upon  this  principle.  To  torture  a  dumb  beast  is  a  crime; 
to  torture  a  man  is  a  greater  crime.  The  person  who 
transgresses  is  the  same  in  each  instance;  but  the  different 
worth  and  dignity  of  the  objects  upon  whom  his  action 
terminates  make  the  difference  in  the  gravity  of  the  two 
offenses.  .  .  . 

"  That  endless  punishment  is  reasonable  is  proved  by  the 
preference  of  the  wicked  themselves.  The  unsubmissive, 
rebellious,  defiant,  and  impenitent  spirit  prefers  hell  to 
heaven.  Milton  correctly  represents  Satan  as  saying:  'All 
good  to  me  becomes  bane,  and  in  heaven  much  worse  would 
be  my  state.'  ... 

"  That  endless  punishment  is  rational  is  proved  by  the 
history  of  morals.  In  the  history  of  human  civilization 
and  morality,  it  is  found  that  that  age  which  is  most  reck- 
less of  law,  and  most  vicious  in  practice,  is  the  age  that 
has  the  loosest  conception  of  penalty,   and  is  the  most 


320  AN  OUTLINE  OF  LOGIC 

inimical  to  the  doctrine  of  endless  retribution."      (North 
American  Review,  Vol.  140,  p.  153.) 

11.  Further  arguments  for  reduction  to  syllogistic  form 
may  be  found  in  North  American  Review,  Vol.  147,  pp. 
121-149;  Vol.  133,  pp.  550-9;  Cosmopolitan,  Vol.  34,  pp. 
597-9. 


INDEX 


A 


Absolute   and   relative   terms, 

the  fallacy  of,  44 
Abstract  and  concrete  terms, 

the  fallacy  of,  47 
Abstraction,  5 
Accident,  the  fallacy  of,  38 
Agreement,    the    Method    of, 

109 
Aikins,   101,   197 
Ambiguities,   why,   are  classi- 
fied, 38 
Ambiguity,     illustrations     of, 

24;    the    definition    of,    29; 

and  classification,  23 
Analogy,     the     definition     of, 

161;     the    value     of,     164; 

false,   162;    the  relation  of, 

to   circumstantial   evidence, 

166;   and  classification,  162 
Angell,  262 
Argument,    the    definition    of, 

2;    the,   for   scepticism,  236 
Arguments,  incomplete,  93 
Argumenlum      ad      hominem, 

and  ad  populum,  105 
Aristotle,   and   the   syllogism, 

51;    and  the   fourth   figure, 

77 
Association  of  Ideas,  203 
Assumption,  false,  93 
Authority     of     the     test     of 

truth,  236 

B 
Baker,  33 

Begging  the  question,  93 
Belief,    to    what    extent    our 
interests   may   properly   de- 
termine, 242;  and  evidence, 
246 


Berkeley,  256 
Bosanquet,  8,  232 
Buckley,  180 


C 


Categorical  syllogism,  the,  65 
Causal  connections,  the  proof 
of,     123;     the     method     of 
studying,  128;  the  proof  of, 
as   dependent  upon  number 
of  instances,   137 
Cause,  the  definition  of,  123 
Causes,   plurality  of,   132 
Certainty,     probability     and, 

191 
Chance,  see  Probability. 
Circle,  reasoning  in  a,   100 
Circumstantial  evidence,  anal- 
ogy and,   166;   and  the  test 
of  truth,  170;  the  definition 
of,    170;   examples  of,   172; 
the  fallacies  of,  194;  deduc- 
tion, induction,  and,  233 
Classes,  concepts  and,  6;   the 
inclusion   and  exclusion   of, 
68;   judgments  of  probabil- 
ity   as    based    upon,     149; 
the  constancy  of,  151 
Classification,     the     imperfec- 
tion of,  9 ;  and  class  names, 
11;  analogy  and,  162 
Concepts    and    judgments,    5, 

228;    and  classes,   6 
Concomitant  variations,   143 
Concrete  and  abstract  terms, 

the  fallacy  of,  47 
Connotation,    denotation   and, 

8 
Convergence  of  evidence,  the, 
186 


321 


322 


INDEX 


Conversion,  the  obversion  and, 
of  propositions,  56,  118; 
false,   62 

Creighton,   129,  231 


1) 


Deduction,  induction,  and  cir- 
cumstantial evidence,  233 
Definition,  ambiguity  and,  24; 
the  nature  and  purpose  of, 
30;  and  synonym,  33 
Denotation  and  connotation,  8 
Difference,     the     Method     of, 
128;  plurality  of  points  of, 
129;  merely  apparent  point 
of,    134;    likeness    and,    the 
awareness  of,  4 
Differentia,  genus  and,  30 
Dilemma,    85 

Disjunction,  imperfect,  91,  95 
Disjunctive  syllogism,  84 
Distribution   of   terms,   55 
Doubt,   reasonable,    117,    166; 
the  function  of  reasonable, 
191 
Drummond,  178 


Enumeration,  proof  by,  108 
Experiment    and   observation, 

140 
Explanation,  observation  and, 

213 
Explanations,  competing,  188 
Extension    and    intension    of 

terms,  7 
Evidence,  logic  the  science  of, 

4;  circumstantial,  170 
Evolution   and   circumstantial 

evidence,   176 


F 


Fact,  hypothesis,  theory,  and, 

193 
Fallacy,  the  nature  of,  4 


False  assumption,  93;  the 
definition  of,  95 ;  ambiguity, 
imperfect  disjunction,  and, 
95;  and  the  syllogism,  97 

Figures  of  the  syllogism,  76; 
the  reduction  of  the,  77 


G 


General  and  universal,  40,  123 
Generalization    and    analogy, 

162 
Genus  and  differentia,  30 
Group  comparisons,  125 

H 

Hibben,  64,  93,   151 
Hobhouse,    112,    188,   222 
Hypothetical  syllogism,  81 
Hypothesis,  theory,  and  fact, 
193 


Idea,    see    Concept. 

Induction,  deduction,  and  cir- 
cumstantial evidence,  233 

Inference,  the  definition  of,  2, 
216;  judgment  and,  218;  in 
quantitative  relations,  79 ; 
the  development  of,  228 

Ignoring  the  question,  102 

Intension,  the  extension  and, 
of  terms,  7 

Interpretation  of  proposi- 
tions, 51 

Irrelevancy,  102 


James,    6,    15,    42,    121,    169, 

202,  210,  215,  216,  241,  242, 

250    259 
Jevon's,  17,  87,  111,  144,  230 
Judgment,     concept     and,     5, 

288;    and    proposition,    52; 

and  inference,  218 


INDEX 


323 


Lafleur,  28,  61 
Language  and  fallacy,  23 
Locke,   256 

Logic,    the    definition   of,    3 
Logical  necessity,  217 
Likeness    and    difference,    the 
awareness  of,  4 

M 

Mathematical  propositions, 
119 

Memory,  observation  and,  198 

Metaphor,  undefined  similar- 
ity and,  12 

Method  of  Agreement,  109;  of 
Difference,  128;  of  Concom- 
itant  Variations,    143 

Middle  Term,  67 

Mill,  4,  109,  111,  113,  128, 
144,   161 

Minto,  14,  17,  66 

Munsterberg,  203 

Mysticism  and  the  test  of 
truth,    247 

N 

Names,      Classification      and 

Class-,  11 
Necessity,  logical,  217 
Newton,  228 


0 


Observation  and  experiment, 
140;  the  popular  notion  of, 
198;    and   explanation,    213 

Obversion  and  conversion,  56; 
false,  60 


Postulate,  uniformity  as  a, 
112 

Proof,  3 ;  the,  of  universal  con- 
nections, 107;  by  enumera- 


tion, 108;  by  the  Method  of 
Agreement,  109;  the,  of 
causal  connections,  123;  the, 
of  causation  as  dependent 
upon  number  of  instances, 
137 
Proposition,  judgment  and,  52 
Propositions,  the  nature  and 
interpretation  of,  51;  cate- 
gorical and  conditional,  53; 
the  quality  and  quantity  of, 
53;  the  obversion  and  con- 
version of,  56;  mathemati- 
cal, 119 
Probability,  148;  judgments 
of,  as  based  upon  classes, 
149;  the  nature  of,  153;  how 
judgments  of,  are  made 
more  accurate,  155;  the  prin- 
ciple implied  in  estimates 
of,  155;  function  of  num- 
bers in  estimates  of,  156; 
as  based  upon  individual 
resemblances,  157;  and  rea- 
sonable doubt,  166;  and  cer- 
tainty, 191 


Q 


Qualities,  the  subjectivity  of 
sense-,  255;  primary  and 
secondary,  263 

Quality,  the,  of  propositions, 
53 

Quantitative  relations,  infer- 
ence in,  79 

Quantity,   of   propositions,   53 

Question,  begging  the,  93 


11 


Reasonable  doubt,  117,  166; 
the    function    of,    191 

Reasoning  or  inference,  2, 
216;  Sorites  or  chains  of, 
78;  in  a  circle,  100;  the 
nature  of,  216;  the,  of  ani- 
mals, 223 


324 


INDEX 


Reduction,  77 

Romanes,  177,  246 

Royce,  204 

Rules  of  the  syllogism,  70 


S 


Scepticism,  the  argument  for, 
236;  the  criticism  of  the 
argument  for,  238;  unrea- 
soned, 240 

Sense-perception,  the  problem 
of,  255 

Sense-qualities,  the  subjectiv- 
ity of,  255 

Sidgwick,  7,  31,  141,  161,  165 

Similarity,  undefined,  and 
metaphor,   12 

Sorites,   78 

Stout,  259 

Syllogism,  the  categorical,  65; 
the  purpose  of  the,  65;  the 
definition  of  the,  66;  the 
parts  of  the,  66;  the  rules 
of  the,  70;  the  figures  of 
the,  76;  the  function  of  the, 
90 

Syllogisms,  hypothetical  and 
'disjunctive,  81;  the  rela- 
tion of  categorical  and  con- 
ditional, 88 

Synonym,   Definition  and,  33 


Terms,  the  definition  of,  7; 
the  extension  and  intension 
of,  7;  absolute  and  relative, 
45;  abstract  and  concrete, 
47;    the  distribution  of,   55 

Test  of  truth,  182;  circum- 
stantial evidence  and  the, 
170;  the  authority  of  the, 
236;  the  non-rational  basis 
for  the,  240;  mysticism  and 
the,  247 

Theory,-  hypothesis,  and  fact, 
193 

U 

Uniformity,  the  principle  of, 
112;  as  a  postulate,  112 

Universal  connections,  the 
proof  of,  107 

Unreasoned  scepticism,  240 


Vagueness,  17 

Variations,    concomitant,    143 

W 


Whately,  102,  103 
Words,  see  Language. 


cul(  ^  «  P  A 


4^rtJ(.  0  i  J 


AIT3 
v5  Al 


UC  SOUTHERN  REGIONAL  LIBRARY  FACILITY 


AA    000  807  747 


II  'i 


I  Hi 


I 


i 


